OOC: Laser weapons in MT and PMT: A brief FAQ

[Jagalonia]

Infrared and ultraviolet lasers are indeed invisible to the naked eye.

Dur! They're not in my spectrum.

Obveously you're not as advanced as the rest of us...Hurrdurr.

[Axis Nova]

Bump for spring, and since new stickies are being worked on.

[Zidano The Land of the Great Sakhal]

This has been incredibly useful. This thread has completely nullified my (god-modding) Satellite based laser system. I think I might RP a test launch, but nothing permanent. I do, however, like the sound of a ground based anti aircraft/ICBM shield. Might use that. And the one plonked onto a Boeing 737. May use that but on a differnet plane (for RP purposes). Should definitely be a sticky! I use.

[SquareDisc City]

A nice article. According to Wikipedia the free-electron laser has also been considered for military usage; I like it thematically, it feels more futuristic than chemical or solid state lasers. The issue of dirt on mirrors isn't something that had occurred to me, and will remain an issue (if not an insurmountable one) even in FT settings.

[Samozaryadnyastan]

Off topic, I know, but apparently the two posts I made on the last page (and the half a page prior) were 'unread'.
How does this occur, exactly?

[Zidano The Land of the Great Sakhal]

Off topic, I know, but apparently the two posts I made on the last page (and the half a page prior) were 'unread'.
How does this occur, exactly?

No idea.

On another seperate point, your flag is fucking awesome IMHO. Great work.

[Samozaryadnyastan]

Not my work
Russian Ministry of Defence flag.

[Axis Nova]

Yearly bump.

This still isn't in an info sticky and it really should be.

[Velkanika]

Yearly bump.

This still isn't in an info sticky and it really should be.

I agree with that sentiment. Has this been added to any of the basic military concept guide compilations yet?

[Haishan]

I feel like contributing text to the thread, being a laser user in RP and all. Note that I never written in a way of advice so it might need some community help to ease the text a little bit.

Also serve as a bump.

There are a lot of different types of lasers, but the only ones that have been seriously studied for military useage in real life are chemically powered lasers, and solid state lasers.

If we regards technicality of words and semantics, it's more appropriate that to state electrically-powered lasers are being studied rather than the term solid state lasers. This is because of recent AFRL effort on coupling diode pumping with alkali vapour lasers to combine best of two worlds; electrical efficiency of diode pump and, good beam quality and superior thermal properties of gas lasers.

This is neither chemically-powered or strictly solid-state in a sense thus the term electrically-powered. Then there's EOIL which is configured to use electrical discharge mode method in order to excite gaseous lasing medium.

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Who are (in real life) researching Laser Weapons?

Currently there are two kind of parties working on laser weapons, namely State entities and private corporations which are either by the request of their host nations or as technology demonstrators to invoke interest for future funding. States that have or currently working with laser weapon programs or have expressed interest with laser weapons are China, France, Germany, India, Iran, Israel, Japan, USSR/Russia, United Kingdom, USA and South Korea.

I won't go on detail regarding Japanese, Indian, Iranian, South Korean and United Kingdom efforts in laser weaponry since there's very little information available but there are online mentions regarding them. Japan and South Korea effort could be said to be motivated by North Korea missile threat as per this link and this respectively.

This link details Indian effort as headed by DRDO. This link might be speculative but it indicates Iran interest on getting a laser weapon. United Kingdom program is briefly detailed by this link.

Before I delve further into the topic, note that I use the term "laser weapon" rather loosely, that it also includes blinder/dazzler-type weapon (designed to blind than kill) rather than the usual repertoire of ordinary burning-through lasers. Now the following sections briefly explain the history and any current available information on the respective States that have such weapon programs.

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CHINA

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Chinese laser weapon research begin in its earnest circa 1960s, originally under a program called Project 640-3 as sanctioned by Chairman Mao Zedong ^[1]. It's approximated that around 10,000 personnel are currently working to advance the Chinese HEL program which includes 3,000 engineers in around 300 scientific research organizations in China based on a 1999 paper authored by Mark Stokes.

Around 40 percent of this intensive R&D are devoted to military applications ^[2]. Current known product example of Chinese laser weapon programs is ZM-87, a high powered tactical laser blinder manufactured by Chinese Norinco, designed to damage sensitive electro-optics on missiles, human eyes, cameras and the likes.

This link also talks about handheld version of ZM-87 with more pictures than the wiki article. [3] further mentioned that Norinco may have adapted ZM-87 system to be used as a complement for Chinese Type-98 MBT's active protection system (APS) which can be assumed to be analogous to IR jammer portion of Russian Shtora APS.

The ZM-87 however was banned by U.N from further proliferation and production (Norinco was eager to export them at that time) circa 2000 over violation of Protocol on Blinding Laser Weapons. Then it's reported in [4] that China is working on developing Shengang-III/IV, which was claimed to directly compete with Russian and USA's high energy laser weapons.

China development into laser blinders also continued post ZM-87 ban by pursuing non-lethal features as shown in [5] and called as Suzhou (I might be wrong on this, feel free to correct me). While there are no known public literature on Chinese battlefield-grade laser weapons, they're quite serious on developing them as illustrated in [2].

China effort didn't end with the ZM-87 or Suzhou example but instead also extended in anti satellite applications as indicated by [6]. [7] mentioned an alleged incident of China intentionally blinding or degrading US spysats over their passage on the State but [8] stated it might be a laser ranging system used to track satellites.

Combined with China ingenuity to 'adapt' (or copy, take as you will) other foreign technologies, it's a matter of time before they have their very own real weaponized laser capabilities. Whether such weapons will be reliable in the long run is unknown but considering China way of doing things, the Chinese can potentially accomplish what other States done in laser weaponry research for a relatively low cost and fast development times.

Dazzler
500 m to disrupt electrooptical equipments and devices, 400 m to inflict temporary blindness.
Weighs 4.8 kilograms and works for 30 minutes per charge.
Made for special forces and anti-terrorism organizations.
Retrieved from internet.

REFERENCES
[1]- http://www.wnd.com/1999/11/1862/
[2]- http://www.ausairpower.net/APA-DEW-HEL- ... ocId698123
[3]- https://www.strategypage.com/htmw/htair ... 20801.aspx
[4]- http://www.wantchinatimes.com/news-subc ... 2&cid=1101
[5]- http://www.youtube.com/watch?v=KrFpjwsDx-I
[6]- http://www.globalsecurity.org/space/wor ... a/asat.htm
[7]- http://www.theregister.co.uk/2006/10/06 ... ite_laser/
[8]- http://www.aaas.org/news/experts-warn-g ... guidelines

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FRANCE

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The history behind French laser weapon program isn't clear due to lack of information in public literature but [9] claimed the French effort did exist and directly inspired by Germany's HELEX program circa 1970-1990s. While it's unknown what happened to the State-funded program at present time, a private French effort exists where Thales announced their partnership with Ecole Polytechnique engineering school in Orsay, France to develop a laser weapon for ground and maritime usage ^[10].

Thales effort is further indicated in the ongoing RAPID program, to develop a complement weapon for air defense systems which can be deduced by this pdf. The aforementioned system is named as RAPIDFlash but there's virtually no information available on it online save the pdf. Therefore it can be suggested that France currently do not have an active standalone, State-backed research dedicated for weaponization of lasers but instead utilizing it for civilian purposes and for refining strategic weapons as per [11] in exception of private effort of Thales company and certain academia.

Apart from Thales private effort, current France involvement in high energy laser research can be seen as multinational in nature as indicated by European consortium of the Air Defence – High-Energy Laser Weapon Project ^[12], suggesting that developing battlefield-grade lasers from the get-go require considerable amount of technical know-how, funding and time. In terms of NS these requirements may not even bother in the slightest but depends on the user on how to view and fit weaponized lasers into his/her own IC continuity.

REFERENCES
[9]- http://laserstars.org/biglasers/continuous/helex.html
[10]- http://www.samizdata.net/2008/12/french-laser-we/
[11]- http://www.liveleak.com/view?i=184_1347467415
[12]- http://proceedings.spiedigitallibrary.o ... id=1390597

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GERMANY

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Germany laser weapon research begun with HELEX program circa 1970s where Federal Ministry of Defense of Germany instructed Diehl Gmb and, MBB corporations to work on a joint industrial project to realize a 10.6 micron CO₂ gas dynamic laser ^[9]. Similar to the French ONERA laser weaponry program, the outcome of HELEX program is currently unknown thus to be assumed now defunct.

However, renewed German efforts in form of private corporations such as MBDA Germany and Rheinmetall Defense can be said to switch German focus from developing Gas Dynamic Lasers (GDLs) into electrically powered solid state lasers. [13] and, [14] respectively indicate their current success on developing such kind of weapons but whether they're currently battlefield-ready is unknown.

[15] additionally illustrate current laser demonstrator capabilities produced by Rheinmetall Defense while [16] details Germany laser weapon research in terms of MBDA history. What is certain however, the two private efforts are seeking to use weaponized laser just like Thales effort, presumably to quickly capitalize on potentially large air defense market opportunity enabled by rapidly advancing solid state laser technology.

REFERENCES
[13]- http://www.ainonline.com/aviation-news/ ... plications
[14]- http://www.defencetalk.com/successful-t ... ons-38500/
[15]- http://singularityhub.com/2013/01/07/ge ... -1km-away/
[16]- http://www.mbda-systems.com/innovation/ ... s/history/

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ISRAEL

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Israel involvement in weaponization of lasers begins through their joint effort with USA to develop Nautilus Laser System (aka Tactical High Energy Laser or THEL) circa 1996 ^[17] due to Israeli recognition of ballistic missile threats in the Middle East particularly Iraqi Scuds during that timeframe. The Nautilus was commissioned by Israeli Defense Ministry with select group of American companies backed by the US administration and the selected final developer was TRW (now part of Northrop Grumman) ^[18].

The Israel then commissioned another design, which is MTHEL that is, THEL on wheels presumably to increase the effectiveness of the chemical lasers to rapidly response to multi vector/sector threat environment of Middle East. While THEL and MTHEL were largely successful to intercept various threats ranging from mortars to homemade rockets ^[19], Israel decided to pull out of the program for reasons unknown and subsequently Nautilus program was terminated circa 2007.

This cancellation may be explained in [18] that the program have exceeded its estimated budgets and there were valid concerns as illustrated by Ghoshroy over usage of dangerous chemical reactants used to power the hydrogen fluoride laser ^[20]. He also highligthed the tracking weakness of Nautilus, displaying obvious skepticism on the toxic chemicals-powered weapon.

Nevertheless, Dr. Oded Amichai, an expert in Israeli homefront defense calls renewed effort on further developing the Nautilus system into "Skyguard", which is aimed to protect airports from terrorist attacks ^[21]. Concerns on the bulky Nautilus and toxic reagents used then lead to switch of laser type being considered where a new effort initiated by Rafael Advanced Defense Systems to develop solid state laser which was announced in Singaporean Airshow 2014 ^[22].

It's to be suggested that the company recognized the need for a cost-effective air defense system to be paired with Israeli Iron Dome system, particularly where the cost of each Iron Dome interceptor reaches in the hundred of thousands ranges in contrast of low cost homemade rockets threat presented by terrorist groups in vicinity of Israel. The system, dubbed as "Iron Beam" and funded by the Israeli Government is expected to be battle ready in two to three years provided enough funding ^[23].

REFERENCES
[17]- http://www.globalsecurity.org/space/systems/thel.htm
[18]- http://en.wikipedia.org/wiki/Tactical_High_Energy_Laser
[19]- http://imda.org.il/english/Defenses/def ... ssileId=30
[20]- http://www.bbc.com/future/story/2012120 ... s-shine-on
[21]- http://www.jewishpost.com/news/Dr-Oded- ... srael.html
[22]- http://www.janes.com/article/33647/sing ... -iron-beam
[23]- http://en.wikipedia.org/wiki/Iron_Beam

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USSR/RUSSIA

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As one of world superpowers that once rivaled USA, Soviet Union begun its highly secretive high energy laser research circa 1960s upon A.A. Grechko, the Deputy Defence Minister (subsequently, USSR Defence Minister) request to M.V. Keldysh, the President of the USSR Academy of Sciences on the possibilities of using lasers for military purposes. It's said that Soviet research was initially prompted due to difficulties encountered in anti ballistic missile programs in the early 1960s ^[24].

The massive Soviet effort similarly parallel American effort on laser weaponization where it's believed that they have similar if not slightly higher competitive position in contrast of USA ^[25]. This Soviet effort was also speculated in [25] and [26] to be several times larger than US efforts, with some ten thousands of scientists, engineers and dozen of R&D facilities involved in the Soviet laser effort.

[24] illustrated that the Soviet effort is centered around two massive programs namely "Omega" and "Terra-3" on realization of HEL weapons for wide variety of purposes ranging from anti-satellite work to air defense. One known company working with the Soviet program is Almaz-Antey, on feasibility of using CO₂ GDL for mobile air defense purposes ^[27].

The Soviets were also working on developing an analogue to American Airborne Laser Laboratory aircraft as indicated by Almaz/Beriev A-60 project which first flown in 1981 and one of the aircraft configuration, a nose-fixed laser director was adopted around two decades earlier than when YAL-1A program was defined ^[28].

While it's generally assumed in [27] and [28] that the Soviet effort didn't precipitate into a workable system, there were at least two technology demonstrator of Soviet laser systems namely SLK "Sanguine", a laser unit on Shilka chassis and SLK 1K17 "Compression", a multi laser assembly on a Msta-S artillery chassis ^[29]. [30] video link further illustrate these Soviet land vehicles.

[29] additionally disclosed that the Soviets were also working on mounting a prototype laser weapon on a ship circa 1984 where the piece, named as "Foros" and mounted on a trawler successfully destroyed a low flying missile in static maritime conditions. This naval effort subsequently morphed into "Aydar" program under the purview of Soviet Navy, in order to mount the most powerful Soviet military laser on "Dixon", a fleet auxiliary dry cargo ship.

The apparent speed and extent of Soviet laser research can be further detailed by a concerted effort on bringing a GDL into space; the Soviet Union had marked the Polyus-Skif as one of top priority space project ^[31] which military design is intended as a direct, crash basis answer to American 1983 Strategic Defense Initiative program announced by Ronald Reagen ^[32].

This craft, termed as Polyus-Skiff DM is described as a Soviet attempt on testing a spaceborne laser upon consideration of difficulties encountered in ground-based lasers for ASAT purposes ^[33]. The prototype however failed to achieve orbit in one piece due to certain technical problems and the apparent hastiness of the project being conducted but [32] stated that should Polyus-Skiff DM was successful, it could change the outcome of then-ongoing Cold War between the Union and USA.

Nevertheless, due to technology limitations of that time, space race with the Americans and, subsequent collapse of Soviet Union at the end of Cold War, it's to be assumed that these laser weapon programs are now defunct. At the present time however, the new Russian Federation have resurrected the A-60 flying laser program a bid to counter-act American continued effort on laser weaponization ^[34][35].

Whether the new Russian program can progress up to same advanced level of American effort remained to be seen but it shouldn't be expected as a surprise due to strong Russian background and history on developing lasers as per [24].

REFERENCES
[24]- http://psi.ece.jhu.edu/~kaplan/IRUSS/En ... Lasers.pdf
[25]- http://www.foia.cia.gov/sites/default/f ... 850305.pdf
[26]- http://www.larouchepub.com/eiw/public/1 ... egic_d.pdf
[27]- http://www.ausairpower.net/APA-DEW-HEL- ... ocId952035
[28]- http://www.ausairpower.net/APA-DEW-HEL- ... TocId92900
[29]- https://sites.google.com/site/tankslase ... tanks-ussr
[30]- http://www.youtube.com/watch?v=kIhfT3f8bx8
[31]- http://www.wired.co.uk/news/archive/201 ... ite/page/2
[32]- http://www.astronautix.com/craft/polyus.htm
[33]- http://fas.org/spp/guide/russia/militar ... lasers.htm
[34]- http://www.theregister.co.uk/2010/09/06 ... ies_again/
[35]- http://rt.com/op-edge/soviet-airborne-l ... arted-600/

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USA

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US effort in laser weaponization could be said to start on early 1970s where Department of Defense found it's theoretically feasible to mount a laser on a flying platform based on input from Dr. Edward Teller, one of creators of American hydrogen bomb ^[36]. The US can be seen to take multi-service approach on developing laser weapons as per [36] where it details a concerted research effort between USAF, US Army and USN each with their own laser projects run in parallel.

The most prominent of all of these projects would be the Airborne Laser Laboratory (ALL) under USAF wings which represent US first airborne laser and large scale experimentation on feasibility of integrating a laser weapon to a military service. The technical knowledge gained from ALL is then transferred into developing YAL-1 system circa 2001 ^[37]. Another factor that made YAL-1 program feasible is design of deformable mirrors gained from Reagen's 1981 Strategic Defense Initiative that seek to put anti ballistic lasers in orbit ^[38].

Before the YAL-1 program proceeded however, the US also signed a memorandum to develop a ground-based chemical laser with Israeli government ^[17][18], presumably also made feasible with lessons learnt from the ALL program. It's to be suggested that the termination of Nautilus program have prompted the US government to pursue the YAL-1 program via joint USAF-Boeing effort even though the scope of both programs are markedly dissimilar where Nautilus was disclosed for terminal defense while YAL-1 was disclosed for countering ballistic threats during their boost phase.

Mirroring the ALL success is advancement of Space Based Laser (SBL) project underneath the Reagen's SDI program circa 1980-1999s ^[37] that also seek to place a chemical laser into orbit analogous to the Soviet Polyus-Skiff DM attempt. While the SDI have been terminated citing abnormal costs involved with it, the SBL program continued to result in a prototype and successful Earth-side testing of Alpha chemically-powered laser, the core of the SBL system ^[38].

[38] further suggested that the SBL project can lead to an actual US operational spaceborne laser demonstrator in 2010 but lack of additional acknowledgement in public literature suggests either the program had gone into veil of secrecy or terminated due to budget slash or not pursued on avoiding militarization of space. [39] and [40] however hinted the SBL program is still alive and continued to be developed underneath USAF.

Moving back to Boeing ABL program, the YAL-1 was particularly successful on intercepting training munitions but reconsideration on the laser obvious problems (such as toxic reagents) lead to its termination circa 2007 ^[41]. These terminations were also said to be caused by huge developmental costs associated with them, which have made the US Congress to shut down the said laser programs.

Undeterred by the cancellations and wavering political support, the US military continued to pursue laser weapons ^[42] by soliciting help from numerous defense contractors and private developers such as Boeing, Raytheon, Northrop Grumman either through Department of Defense funding or direct military branch cooperation (i.e US Army) or through DAPRA solicitations. This marks US switch from megawatt class chemical lasers to solid state but low powered laser systems, apparently to support mobile warfare visualized by US military commanders.

Rapid solid state laser improvements in the turn of century then saw multiple technology demonstrators made by US companies; Boeing have demonstrated a 10 kW laser weapon mated to the Avenger air defense vehicle ^[44] and subsequently worked with US Army on developing HEL-MD system ^[45]. The same HEL-MD program also saw participation of Lockheed Martin to offer an alternative configuration to Boeing system ^[46].

Raytheon on the hand have successfully demonstrated their prototype dubbed as LADS - Laser Area Defense System in designated terminal air defense role circa 2007 using commercial components such as industrial grade fiber lasers by integrating a 60 kW laser system to a Phalanx air defense system ^[47]. Another premier US defense company, Northrop Grumman announced the successful testing of its scalable laser system dubbed as FIRESTRIKE ^[48].

DAPRA, the Defense Advanced Projects Agency have also a hand in the game; through the HELLADS program, it seeks to combine the reliability of solid state lasers with thermal characteristics of liquid based lasers. The HELLADS program is designed to develop a mature, low weight laser system that can be used in airborne applications for defending the user from common anti air threats ^[49].

Paralleling the US solid state laser effort is ONR, Office of Naval Research joint program with Boeing to develop a Free-Electron Laser system starting from 1980 due to advantages presented by FELs on tunability of their laser emissions to meet various mission objectives, especially challenging near-ground and maritime conditions ^[50]. However to date, the development of FEL is to be assumed very difficult based on lack of information or success regarding the ONR effort in public literature.

Apart from these demonstrators, few US laser weapons are in or nearing current service such as the ZEUS-HLONS system ^[51] and, the LaWS system trialed on active duty of USS Ponce ^[52]. It seems that whether these systems to be pushed into service depends on USA political climate, funding and the preparedness of US military to accept the new weapons.

REFERENCES
[36]- http://www.ausairpower.net/APA-DEW-HEL- ... ocId408377
[37]- http://fas.org/spp/starwars/program/sbl.htm
[38]- http://laserstars.org/biglasers/continuous/sbl.html
[39]- http://fas.org/sgp/crs/natsec/RS20859.pdf
[40]- http://archive.wired.com/science/discov ... ntPage=all
[41]- http://en.wikipedia.org/wiki/Boeing_YAL-1
[42]- http://www.ausairpower.net/APA-DEW-HEL- ... ocId937936
[43]- http://spie.org/x39813.xml
[44]- http://en.wikipedia.org/wiki/Boeing_Laser_Avenger
[45]- http://www.boeing.com/assets/pdf/defens ... erview.pdf
[46]- http://optics.org/news/5/4/42
[47]- http://investor.raytheon.com/phoenix.zh ... &ID=948611
[48]- http://www.irconnect.com/noc/press/page ... l?d=254109
[49]- http://www.darpa.mil/Our_Work/STO/Progr ... DS%29.aspx
[50]- http://www.lanl.gov/science/NSS/issue1_ ... full.shtml
[51]- http://en.wikipedia.org/wiki/ZEUS-HLONS ... _System%29
[52]- http://www.onr.navy.mil/Media-Center/Pr ... yment.aspx

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Miscellaneous reading for the fancy.

Army’s New Laser Cannon Blasts Drones Out of the Sky, Even in Fog
Laser Gunship Fires; ‘Deniable’ Strikes Ahead?
Directed Energy Weapon Symposium, Munich 2012- Conference expects slow transition to laser weapons
Operational Implications of Laser Weapons by Northrop Grumman

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Who have ready battlefield laser weapons now?

Based on relevant posts in this thread and the references in the above sections, it can be said that currently China, Israel and, USA have operational laser weapon systems with the rest of aforementioned States catching up.

But why use Laser Weapons? Don't boolits work better?

This question is highly situational. What do you want to use a laser weapon for? You need to firstly know where does a laser weapon fits in your tactics and overall doctrine before using them. You also need to know the limitations of laser systems and as per words of anonymous US naval commander, laser weapons aren't supposed to replace other weapons but instead to complement their operations.

So it can be summarized that laser weapons are currently good in low to medium intensity air defense against targets that didn't warrant an interceptor missile (such as UAVs, drones and rockets), blinding satellite systems and blinding electro-optical systems such as cameras. ABL-alike weapon systems are theoretically sound but highly impractical so it's best to assume that laser weapons are only good at terminal defenses.

[The High Tatras]

My nation has "teleforce projectors" that operate essentially as Nikola Tesla described, so obviously realism is not of much concern to me. However, Tesla claimed that his weapon "will bring down a fleet of 10,000 enemy airplanes at a distance of 200 miles". I am considering downgrading the capabilities of my "teleforce projectors", because I am worried that portraying them exactly as Tesla did might be godmodding. What would reasonable (though not realistic) capabilities be for this type of weapon?

[Haishan]

My nation has "teleforce projectors" that operate essentially as Nikola Tesla described, so obviously realism is not of much concern to me. However, Tesla claimed that his weapon "will bring down a fleet of 10,000 enemy airplanes at a distance of 200 miles". I am considering downgrading the capabilities of my "teleforce projectors", because I am worried that portraying them exactly as Tesla did might be godmodding. What would reasonable (though not realistic) capabilities be for this type of weapon?

Since nothing much known on the said weaponry and there's little public literature on it save a few patents, I suggest that you should negotiate the weapon kill rate or effectiveness with the other party that faced it. Given the description provided by Nikola Tesla in conjunction of your recognition of it not being realistic enough, I suggest that trying to apply common realism on it is not recommended on what seems like a 'wonder' weapon.

Therefore in simpler terms, if it's not a realistic weapon, don't apply realism heavily on it but instead apply negotiation and cooperation with the other party on what can it kill or damage or whether it's acceptable to use such stuff in the first place. It will make the RP simpler and cut down potential OOC bickering. Alternatively, the most reasonable number is what the other party is prepared to accept as per my previous points.

[Haishan]

Updated viewtopic.php?p=21646678#p21646678 with references to US Space Based Laser program which aimed to put megawatt range hydrogen fluoride laser in space for anti satellite and anti ballistic missile tasks. It would be great if someone more knowledgeable than me help to further confirm the validity of my post.

Additional blurb with my attempt at guidance writing. Someone more experienced is welcomed to improve the said answer.

I have a laser weapon program now, so which one I should choose?

Firstly you need to define your operational goal of the said system. Is it for terminal counter-munition purpose or anti-satellite or anti-aircraft? After getting that part down, see what does your doctrine require and generally expect from your military systems. Does your doctrine favour static installation or mobility? Then we can now finally decide what kind of laser to use. The following list some of the common examples of laser types being considered for weaponization.

Solid-State (Fiber/Slab)
+Rapidly maturing technology, available right now
+Plug and play, do not need additional support than power and cooling support
-System integration with actual military environment unknown
-Currently low power (below than megawatt ranges)

Chemical (Gas Dynamic, Reactants)
+Mature and field tested, available now
+Very high power, in megawatt ranges (except Gas Dynamic Lasers, historically they can only reach tens or hundreds of kilowatt of power)
-Bulky and need expensive toxic chemicals
-Supplying chemicals used by laser is a big logistical headache
-Durability concerns of fragile assembly

Hybrid (Solid-Liquid or Solid-Gas ala HELLADS, EOIL, DPAL etc)
+Potentially high power scaling
+Combines best features of solid-state and chemical lasers
-Not fully characterized in field conditions
-Full effectiveness haven't been demonstrated, largely experimental

Free Electron Lasers
+Promises high level of tunability and adaptability to mission parameters
+Potentially enable engagement of various targets
-Mostly experimental
-Might be very expensive and bulky

If you're unwilling to read the following block of texts, feel free to read the simplified version of this answer here. Now if you're strictly a realist then only solid state and chemical lasers are for your consideration. Note that different intended role may require different kind of power; it may be wastage to shoot an ordinary mortar with a megawatt chemical laser while a cheaper, kilowatt-level solid state laser can do the job just fine.

The type of laser you selected can also determine the size of the platform for the laser; chemical lasers tend to be huge monsters to house their reactants and all (although GDLs can fit in a truck size, it have far more low power than say, COIL) while solid state lasers were demonstrated to fit into relatively compact packages, obviously at cost of lower effective beam power at range.

This size-power scaling may no longer apply once solid state lasers catches upon high power levels demonstrated by chemical lasers but that would be several decades away given current scientists are still struggling to improve the lasers' wall-plug efficiencies as current solid state lasers are inefficient and unfavourably generate high amount of heat in contrast of their compact form factor promise.

Another factor that must be taken into account is the range of your laser; generally to reach distant targets, you need large amount of power to defeat defocusing effect caused by atmospheric particulates and ensure enough energy is delivered to your intended target. Since generally a laser weapon works by reflecting its beam over its internals multiple times before spewing the laser out, higher power levels also entails larger focusing and director equipments to avoid or delay generated heat caused by internally reflected beams from distorting its optics.

This internal heat can lead to failure of the optics system and subsequently self-destruction of the laser if not accounted for. While adding necessary cooling equipments can partially solve the optic thermal issue, another factor comes into play, namely the focusing limit of your laser optics. Most lasers have a defined diffraction limit on their optics so if they want to go far, they need a suitably sized optics to shoulder the task. This of course further increases the size of your optics to account for defocusing caused by physical diffraction limits entailed by using a smaller optics system.

Say you decided to use adaptive mirrors to solve the diffraction problem (and yes it's one of the way) but note that currently such system is inherently delicate and complex so you're going to have make some concessions, i.e do you want range and fragility or you want shorter effective range and reduced system complexity?

Yet another factor that must be considered is heat generation issue; high power or long duration laser weapons will obviously generate a lot of heat thus require suitable cooling equipments and the space to place them. This also put some kind of power limit of your laser weapon in respect to the space available on your platform where the cooling requirements of a megawatt laser will take so much space that trying to mount it on a Humvee is unfeasible.

As a general rule in my opinion, 5-10 kW will be good enough for ordnance neutralization, anti skipper pirates and optical equipment mission kill. 20 kW-50 kW will do good against most modern UAVs and homemade rockets while 100 kW and above do well against most mortars, artillery shells and missiles. When you start to hit 200-300 kW range, the laser weapon might be useful to be adapted as a pinpoint surgical weapon against soft skinned ground target if mounted on an airborne platform or to be considered used against aircraft and helicopters. Megawatt-range lasers on the other hand might be suited to be used against ballistic threats and potentially near Earth space targets.

Blinding hostile reconnaissance satellites is expected to take around few hundred watts of power since they mount very sensitive equipments to look at Earth. These low power levels also entails temporary blinding but for permanent blinding, special consideration must be taken to the make of the satellite equipment, its position and its distance from you to make your anti satellite laser to work. Then there's atmospheric condition to be considered.

Is it really worth it to have a megawatt ground based laser trying to disable a high flying satellite while coping with obvious defocusing problems presented by tonnes of air in its beam path or just use a low powered one that can only temporarily blind your target? In the end it depends on what you want to do with your laser weapon and whether it makes sense ICly for you to use them.

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SIMPLE ANSWER VERSION

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In much more simpler terms, generally a laser weapon will be limited by a few things. Firstly the cost-economics of power of the weapon in respect of your intended role. It's generally cheaper and easier to use a solid state laser for terminal defenses against UAVs than using a highly expensive, and toxic chemical powered megawatt laser. Then you have doctrine requirement on your system; if you want fast mobile laser unit, then bulky chemical lasers aren't for you.

Another thing you need to keep in mind is what is your expected range of the system? If you want it to go long range, expect it to be large and bulky given to defeat all that pesky air in the way between your emitter and target, your laser will need large amounts of power. Using large amount of powers will cause substantial cooling requirements (it's estimated current chemical lasers are only around 10% efficient and solid state lasers around 30% where the rest of supplied power goes into excess heat) thus needing additional cooling systems which add to total space and cost to your laser in order avoid it from overheating and destroying itself.

This also ties to the aperture size (or 'muzzle') and optic system of the weapon, given generally laser weapon optics have a hard diffraction limit where beyond that point, the laser will start to spread and go all over the place, not concentrated enough for you to point it accurately at the target. The range issue also ties to the expected size of the weapon; by considering the cooling and optics issue, if you want to go far, unfortunately you will be forced to go big with your system. Yes, there's that deformable mirror thing which magically reduce your optics focusing issue but that's a complicated system and will present durability issues.

Then this size issue also ties to the overall system durability (it's easier to damage a big laser considering its fancy internal focusing optics than say a simple short ranged laser with less parts involved) and the cost to build and maintain your laser weapon. So if you want an effective lightspeed weapon, you need to balance between these criteria (power aspect to intended role, range, size and durability) and the tradeoff associated by going a particular design goal. It's to be stressed that different laser types have different advantages and disadvantages. After you take care of these criterion and figured out the tradeoffs you must take, then you can select what kind of laser to use for your intended application.

++++

I want/use a space borne laser yet my friends claim I'm godmodding! Help!

Well to start, first you need to know how does space based laser differs from terrestrial lasers. If you do know the differences between the two, just proceed to the third paragraph of this answer. Generally, since they're in space, they do not suffer traditional problems encountered by terrestrial lasers like thermal blooming (there is no air in space) but they're still limited by heat generation, diffraction limits caused by optics being used and additional problem of trying to get the said system into space in the first place and, to supply/maintain the said laser once it gets there.

This space system will also be vulnerable like any other satellites and can be persistently tracked. Should the space laser try to attack surface target, expect the atmosphere is your worst obstacle; it might be not cost effective to use a space laser on attacking a ground target opposed of traditional cruise missile or ballistic weapons as majority of the laser power will be soaked up by tonnes of air between your laser and the target.

In my view, there's nothing stopping a RPer to use a laser weapon in space considering the precedent set by Polyus-Skiff DM and then Space Based Laser testbed but expect tremendous technical challenges (how do you build the laser to survive the space launch?) and severe limitations (large heat problem and maintenance issue) involved on trying to operate one let alone get one into orbit in respect of current IRL technology levels. If you're still insisting to have and use a space laser in your RP, it's recommended that such system is best discussed and negotiated with the party you're RPing with to see whether it's acceptable to be used in the first place.

[Axis Nova]

Thanks for the extra info, Haishan-- it's definitely appreciated.

[Blakullar]

Question redacted, didn't read Haishan's recent post about laser types, hah. I've been looking for a thread like this for ages, and I will definitely recommend it to others.

[-The Unified Earth Governments-]

:Cough:

Wrong about PMT part....

[Haishan]

Thanks for the extra info, Haishan-- it's definitely appreciated.

No worries, it's the least I could do despite not being a laser weapon expert. I'd appreciate we can get this thread going and to ensure validity of information I and others posited through discussions.

:Cough:

Wrong about PMT part....

Well then, perhaps you could posit your opinion on what is wrong then? We need some useful discussion going; I feel this thread can be more active with constructive discussions. In regards of PMT lasers, I have not yet thought of points to support the topic thus I will currently abstain from discussing it.

---

Now a customary link if someone thinks it's a good idea to crunch some numbers.

Online laser weapon power calculator
Alternative laser power calculator

Additional reading on ABL and the challenges faced using it in IRL perspective.

Assessment of Long Range Laser Weapon Engagements: The Case of the Airborne Laser

[-The Unified Earth Governments-]

Thanks for the extra info, Haishan-- it's definitely appreciated.

No worries, it's the least I could do despite not being a laser weapon expert. I'd appreciate we can get this thread going and to ensure validity of information I and others posited through discussions.

:Cough:

Wrong about PMT part....

Well then, perhaps you could posit your opinion on what is wrong then? We need some useful discussion going; I feel this thread can be more active with constructive discussions. In regards of PMT lasers, I have not yet thought of points to support the topic thus I will currently abstain from discussing it.

---

Now a customary link if someone thinks it's a good idea to crunch some numbers.

Online laser weapon power calculator
Alternative laser power calculator

Additional reading on ABL and the challenges faced using it in IRL perspective.

Assessment of Long Range Laser Weapon Engagements: The Case of the Airborne Laser

The OP is wrong about that tidbit about infantry sized lasers for PMT because PMT is exactly what it says on the tin, its post modern.

And it also comes into conflict with FT because of that.

Ft is usually decided as a tech level that starts at least with FTL, and at least any other stuff that shouldn't be done without said technology (So if you cannot go faster than the speed of light and cannot make any form of reasonable travel, etc, you are not FT, if you RP as a race only that expands itself at light speed or something, then yes you would be FT, but mostly if you are still PMT if you are locked on Earth herself.

This of course can be silly sometimes, sometimes and PMT nation will have more exotic tech then a FT one (Advanced laser rifles, plasma weaponry, etc) while the FT one might not.

Unlike MT and PT, these two techs are generally much more open with what you can do, only early PMT stuff would be limited.

[Axis Nova]

PMT generally implies that you're still following the laws of physics (as opposed to PMT, where anything goes). So no, man portable laser rifles are not going to be a thing in PMT, even if you hook them to an entire backpack full of batteries. The heat issues alone make them impractical.

In any case this is not the thread to argue what is and isn't PMT.

[Haishan]

PMT generally implies that you're still following the laws of physics (as opposed to PMT, where anything goes). So no, man portable laser rifles are not going to be a thing in PMT, even if you hook them to an entire backpack full of batteries. The heat issues alone make them impractical.

In any case this is not the thread to argue what is and isn't PMT.

Now I wouldn't say them to be entirely impractical if we extrapolate from expected raise of laser efficiencies and explore new ideas to cool them. Infact the following idea was considered for one of my planned laser weapon designs but since it's still a mind draft, it's incomplete in some respect. Before discussing the said idea, it's recommended that one reads suggested key points on how to adopt laser weapons for infantry usage, in PMT as illustrated below.

1. Damage mechanism
2. Power supply
3. Cooling
4. Targeting & Electronics

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As reiterated in my previous postings, a laser weapon can be generally be divided into two types in terms of their way of operations, either continuous (CW) or pulsed. CW operation, as its name implies constant lasing at specific amount of time akin to using a long range blowtorch but obviously with great power comes at great cost; all of these processes generate unwanted excess heat. Pulsed operation on the other hand is an intermittent process designed in such a way that the laser heat could be rapidly removed as its cycles between emitting and non-emitting state.

It's to be further suggested that even though laser efficiencies are expected to rise exponentially via the diode-class lasers (cutting edge IRL research hinted at 40% ish wall plug efficiency before amplifiers and all), they still generate considerable heat which may not be suited for the PMT grunt which will use the said flash stick and need to be all stelf-like. Another justification for pulsed op rather than CW could be attributed to short engagement scales normally encountered by such grunt even when using a conventional, bullet spewing weapon (aka assault rifle).

As it's a point and shoot gun, it's more preferable to have the grunt use the weapon minimally, i.e show himself/herself less often to enemy as they might try to kill the guy with such lightspeed weapon first. Thus summing all these points, a useful laser rifle should not expose its user more than necessary and should generate manageable heat loads which can be achieved by going pulsed operation.

One might be wonder how a squirt gun (pulsed laser) is suitable for infantry laser rifle compared to a water cannon (CW laser) thus it's recommended that this conundrum could be solved by using a completely different damage mechanism. Instead of trying to cut the enemy and help him/her cauterizing the said wound, Laser Pulse Detonation (LPD) could be adopted to work with operational constraints of a pulsed laser. In IRL terms, this mechanism is more commonly associated with Pulsed Impulsive Kill Laser (PKIL) or its purported less-lethal name, Pulsed Energy Projectile (PEP) which is being researched by private US companies today.

Simply put the mechanism states that with a quick enough laser pulse, the air on the target can be compressed to intense pressures, breaking the said air into plasma while simultaneously pushing against the target. As soon as the pulse died, this compressed gas region will decompress, causing a tiny explosion and target ablation, independent of target surface or type of laser used. Henceforth, for easily believable PMT laser rifle, it's preferable to operate pulsed in nature and exploiting LPD since such method provide the most justifications for a handheld weapon.

Now this would be one of the first stumbling block for any laser weapon, not yet a handheld one. Due to generally high power consumption of any laser weapon, this put a particular requirement level for the powerplant to enable the laser rifle to work. It's even more advantageous if the said power source can be similar if not lighter than the weight of several conventional bullet magazines as it's to be assumed the grunt will be trading her/his conventional assault rifle to use the laser rifle or using the said flash stick as a complement weapon for his/her combat gear loadout.

One might argue that creation of feasible combat exoskeleton will eventually expand the said grunt carrying capacity to carry both weapons but that's fine given my current assumption is the grunt can only have one primary weapon (either conventional AR or laser rifle). These requirements obviously posts a considerable constraint for the hypothetical grunt as the powerpack must be not only light but also provide sufficient power for the laser rifle to be justified in the first place thus this entails usage of gravimetrically energy-dense powerpack.

For this power supply section, I have two different approaches to handle the said topic, either by going a backpack system or simply using quick-swap power units for the said laser rifle. Both hypothesized approaches have their own strengths and weaknesses which will be illustrated in detail as the following.

Backpack Powerpack

[+] High energy potential with dedicated separate power unit (SOFC, micro gas turbine or thermopower et al)
[+] Large volumetric space for coolant
[+] Can operate with other equipments
[-] Additional weight
[-] Maintenance complexity
[-] Cabling hindrance

Quick swap Powerpack

[+] Unit simplicity, just swap 'batteries'
[+] Does not increase overall load if using lightweight power units
[+] Ease of usage with minimal training, no cabling of sorts
[-] Output might be limited
[-] Cooling could be troublesome, limited volumetric space on weapon
[-] Introduces complexity in logistic chain, need to supply power units to rifle

One might wonder on how could a mere powerpack power a laser but it's to be rectified that by going pulsed LPD operation, the power requirement could be minimized, hence fulfilled to a certain extent. It's to be suggested that miniaturization of solid oxide fuel cells or development of thermopower generators or micro gas turbine to be installed on a backpack unit can provide enough power for the laser weapon assuming useful gains in current IRL research, particularly nanotechnology materials and engineering to miniaturize the said element(s).

It can be further justified that utilizing liquid fuel and the said efficient backpack could theoretically provide enough power to operate the aforementioned pulsed laser rifle given enough emphasis on rapidly advancing nanotechnology to efficiently extract as much as power as possible from the said liquid fuel. Given the laser rifle is more advantageous to be operated in pulsed operation, the backpack unit could provide base energy level to charge up several quick discharge ultracapacitors which in turn will power the aforementioned pulsed laser.

However as illustrated above, a backpack unit might be not feasible for an agile trooper thus an alternative method could be used in form of quick swap power modules akin to swapping magazines. Adopting the battery-magazine method might also grant better handling characteristics than the previous method but as aforementioned, this will put a fundamental cap of laser weapon effectiveness (due to energy density involved, liquid fuel is predicted to have higher gravimetric energy density) rather than having an external power supply unit.

If one suspects it's impossible to have suitable material for the second method, recall that current IRL research have made graphene/CNT battery-capacitor units that rival current lithium ion batteries in terms of gravimetric power density. Therefore, supplying required power to the said laser rifle with the quick swap module will probably relate on designing proper energy module to both retain power (battery component) and provide burst power (ultracapacitors) to operate the laser rifle in pulsed operation.

Thus it can be suggested and extrapolated that these solutions will get better henceforth legitimate enough to be considered for the laser rifle with due respect to natural technology progression of PMT.

As aforementioned previously and as pointed by Axis Nova, cooling a laser rifle might posit considerable headache. But if one uses pulsed operation to limit heat generation, the said issue could be somewhat mitigated. There's two approach to this cooling requirement as previous discussed topic but firstly there must be some sort of declaration made; 1) assumption of better lasing medium that can withstand extended heat loads 2) nanostructured assembly to dissipate heat rapidly 3) usage of specialized heatsinks such as diamond or boron nitride. Note that this declaration is no means exhaustive but lets focus on what is assumed before hand.

Powerpack Radiator

It can be assumed that utilizing an external powerpack, there will be an integral radiator built into the said unit and heat transfer from the laser medium could be facilitated using the same power cord attached to the laser rifle. There's two ways of doing this, either by using liquid convection or solid conduction. Usage of liquid convention will require a dielectric, non-flammable fluids with high specific heat capacity which can be extrapolated from current known fluid coolants such as PAO olefins.

After selecting the proper working fluid, one can then wonder on how to remove heat from the said fluid thus it can be suggested there is two methods of achieving so, vapour-liquid cycle or straight up fluid flow through a physical radiator with large surface area. Going liquid conduction however entails there must be some sort of propulsive power to cycle generated weapon's heat thus it can be once again suggested, two ways of doing it which is either utilizing a small scale impeller pump or using electrohydrodynamic pump.

Solid conduction on the other hand require a flexible material to conduct the said heat to a dedicated radiator from the laser rifle while simultaneously shielding it from the user. If one managed to make a flexible diamond or any other similarly useful material, it could be considered. Note that there exist certain differences between the two methods; liquid convection cooling means the user will deal with a fluid which might get unwieldy to handle while solid conduction cooling means should the conductor have any physical defects, this might cause reduced heat transfer efficiencies.

Then one must consider on how to remove the said heat after it have been removed from the laser weapon thus it's also important to concern on the powerpack's cooling method. Traditional heat exchanger flowing method might work with liquid conduction but it will require high surface area to rapidly disperse collected heat and this means nanostructured heat sink surfaces.

It's uncertain whether solid heat conduction could work with traditional heat exchanger flowing method thus it's to be suggested that one look at alternative modes of heat dissipation, such as thermoacoustic or magnetic-refrigeration. In terms of thermoacoustic-based cooling, it's theorized that the said heat conductor could transfer generated heat into a specialized substrate that will later get activated with certain frequencies of sound for the cooling effect.

Recall that current IRL thermoacoustic cooling have theoretical efficiency of around 40% thus in PMT this method might be a viable one, especially since the method do not involve any moving parts. On magnetic-refrigeration method, the said heat could be conducted to specialized magnetocaloric materials which will accordingly get heated to radiate the said heat. By cycling the said materials inside a magnetic field, the cooling elements will get 'cooled' with application of the magnetic field. Like thermoacoustic cooling, magnetic refrigeration represent less fiddly parts compared to conventional liquid heat exchangers but mechanical point of failure still exists, being the rotating magnetocaloric materials.

Integral Weapon Cooling

If one prefers to have the necessary elements integrated with the said weapon, the task could get harder than simply having an external unit given there's little volumetric space to integrate a useful heat radiator. One might consider the idea of liquid conduction akin to WW2 water-cooled machine gun but this will put a certain limit on the weapon operation before it overheats.

It's also necessary to use a fluid with high heat capacity thus water could be used given its lucrative properties (high latent heat capacity, et al). However, it can be argued that this method could not provide heat conduction fast enough thus it might be necessary to improve the heat conduction process to the said working fluid, by pursuing nanostructured surface area to efficiently remove heat. If it's still suspected such conventional method could not work, it's necessary to look into exotic solutions such as metamaterials.

Current research into metamaterials point to possibility of having hyperbolic thermal metamaterials which is a nanostructured material that can efficiently conduct heat based on its structure opposed to traditional material properties of yore. This exotic research also points to harnessing these tiny structures to exhibit heat manipulations via evanescent plasmonic waves (pseudo photon-electron cloud on the material surface) to concentrate them or quickly emit them as if heat is a kind of fluid etcetera.

It's important to note that in this thermal metamaterial concept, heat is thought as molecular vibrations thus by arranging the atomic configuration of the conducting substrate, this molecular vibration could be controlled thus channeling heat rather than making it diffuse evenly throughout a material. In simpler terms, heat can be said analogous to 'water' and these thermal metamaterial structures are the 'water' bottles, ducts and dams.

The thermal metamaterial of course could be adopted for any of the cooling methods to quickly control heat flows but there could be a significant challenge on ensuring its effectiveness given its heat mechanism depends on the material's structure. While it sounds very promising, it's to be noted that battlefield conditions could involve large amount of vibrations thus specific care might be needed to preserve such thermal metamaterial from structural fatigue and damage in order to remove heat properly.

The disadvantage could be easily overlooked as it's possible to control where does the heat go as hinted in earlier paragraph. For an example, a laser rifle could have a super efficient thermal metamaterial sink to transfer heat from the laser media to the conductor at the speed of light (pun intended) which conductor can also transfer heat at the same speed and avoid heat leakage by proper structural design.

The said carried heat then could be radiated via a specialized thermal metamaterial emitter to rapidly disperse the channeled heat into the surrounding. Given the exotic concept can transfer heat at the speed of light compared to relatively slow conventional heat diffusion process, it might be advantageous to combine it with other methods of cooling to rapidly disperse weapon's heat. It's certain however, an integral weapon cooling system might present some burn hazard should the grunt holds the rifle thermal radiator by mistake.

Unfortunately this section will be relatively brief given current electronics can easily serve in the laser rifle targeting role. For the targeting issue, one could adopt how ABL does it, by having a secondary low powered laser to gauge necessary information from standoff distances. With due consideration to PMT technological progression, it can be assumed that this capability brought by bulky equipments of yesteryear can be miniaturized into a small module akin to how XM-25 combines several advanced functions into a single unit.

It's suggested that the targeting mechanism can use the low powered laser unit to derive atmospheric conditions, target interrogation, range estimation, coded targeting lasing for networked fire and any other suitable capabilities as the designer sees fit. However, certain elements are strongly suggested to exist for efficient operation of the laser rifle, mainly real time atmospheric telemetry (wind speed, moisture, atmospheric particulate count), target interrogation and damage assessment for automatic calibration.

If one wishes to simply ditch these features, it's possible but it's predicted the resultant laser weapon will not be properly optimized for its range of operations thus exhibit inappropriate inefficiency in contrast of its usage. For an example, a simple laser rifle with none of the aforementioned features might waste too much power to get into the target just incase there's air turbulence or obscurants blocking the laser shot. The issue is particularly important if one adopts the pulsed LPD scheme as the projected pulses could dissipate before even reaching the target due to miscounting atmospheric variability in between.

---

Note that my conjecture is, PMT laser rifle is feasible if one pays close attention on solving the aforementioned problems associated to them but since no one really made any workable laser rifle IRL, that doesn't mean it will be never be built. A designer should be open to new ideas and tactful to adopt certain useful elements for such endeavor thus lets move on to what I have in mind for a potentially workable concept.

As hinted in my short dissertation, my concept would be in two forms namely a laser rifle + backpack unit or simply a standalone laser rifle integrated with necessary elements. By going backpack, this essentially moves the center of power and cooling from the weapon and into the said external unit which can give some slight liberty on designing the laser unit but this posit some inflexibility on using the said weapon due to cabling and maintenance involved with the complex system. The arrangement might work great for exoskeletonised trooper but will probably suck for troopers that prefers to be agile in combat.

On the other hand, my standalone laser rifle concept calls upon quick release and swap power units, integrated with specialized hyperbolic thermal metamaterial solid cooling system on available surfaces of the weapon, like the sides of the gun. This cooling system can be further improved by introducing liquid cooling loops using phase change materials such as water, to act as a boiling working fluid and since the metamaterial can be engineered to focus the said heat at lightspeed, the thermal transfer could be fast between the laser and the fluid circuit.

While the laser rifle concept could have lower parameters than the previous concept, training new grunts to use the weapon can be effectively simplified given the laser rifle will not differ much from conventional AR. It's to be rectified that maintenance of standalone laser rifle can be envisioned as manipulating block of legos in order to reduce complexity dealing with such precise weapons.

Alternatively, why bother with cooling at all? What if there exist an other way to achieve a useful handheld laser rifle? Soviet Union tried the concept with their laser pistol whereby a certain pyrotechnic charge generate the necessary flash pump for the laser medium to work while disregarding cooling issues. Taking this concept to PMT, one could envision a design where the laser rifle essentially use an energetic chemical compound to flash pump the laser unit but this method will be reliant on how good is the photonic converter and amplifier(s) connected to the said chemical activation chamber.

If one pursues the concept, it's expected a laser rifle with a dedicated power supply will outperform the concept but in terms of simplicity, the former wins by virtue of being simple in theory and execution. If the laser media have been damaged, changing it could be as trivial as changing a conventional AR barrel.

The ball would then lies on how the rifle is supposed to damage the enemy thus if the concept of pulsed LPD is selected, it's just a matter of adding a specialized blinder/photonic delay to the output laser beam to achieve pulsed effect. The said cartridge-using laser rifle will be analogous to conventional AR in exception it can get heated quite fast with extended usage.

A second alternative exist, if we change how the laser is supposed to operate in the first place. Conventional lasers ordinarily relies on electric field or chemical reaction or external photon pump but all of them involves one central idea, population inversion whereby a particular group of atoms are excited to high energy levels and then return to ground state by emitting photons.

Therefore if we can achieve this population inversion and set the resultant excitation in the same phase, we have a laser no matter what kind of method is used to trigger the said inversion. The following concept is a pretty far-out one considering it's mainly theoretical work IRL but it's possible to use specifically crafted nanostructures to achieve 'population inversion' by using heat. Recall that thermal hyperbolic metamaterials manipulate heat by the virtue of their atomic arrangement thus if an appropriate structure is selected, we could have a heat-powered laser by channeling the said heat into specific resonant structures for the population inversion to take place.

Yes, a laser rifle that uses heat to lase and if one still suspect that it wouldn't work due to cooling issues, note that such issue do not exist as the weapon will automatically cool itself by emitting the laser. If the heat-powered laser is further integrated with the thermal metamaterial idea, one can simply need a heat source for the said weapon to work minus the cooling issue and the heat source could be anything that is proper for the weapon to work.

An important caveat exists in terms of the nanostructured laser medium and the weapon casing as they're likely to have some kind of heat limit before failing. This concept also assumes the said mechanism can be experimentally verified and efficiently actuated.The listed link illustrate the idea in detail.

Considering it's PMT we're talking about, how much advanced or legitimate a one's laser rifle will eventually fall square on how the user and the other party willingness to accept such concept into a RP. In my opinion however, a laser rifle in PMT can be made if not somewhat crude. As always, I appreciate it if someone else can improve upon my answer. Since I cannot properly estimate the balances and checks of a laser rifle, I can only give arguments in conceptual terms on why it can be feasible provided the correct elements involved.

[Axis Nova]

...a laser that cools itself by firing? That does sound kinda backwards, but nothing you've said regarding metamaterials seems wrong or illogical so far.

[Haishan]

...a laser that cools itself by firing? That does sound kinda backwards, but nothing you've said regarding metamaterials seems wrong or illogical so far.

Not backwards. Since the heat is what causing population inversion in the gain medium, thus it's logical that this heat energy is being converted into coherent beam of photons as the excited medium returns to ground state therefore simultaneously cooling the laser media being heated should the said medium is emitting a laser beam.

Additionally, there's another version of self-cooling laser (which I'm conceptualizing for Haize sekrit weapon but decided to disclose anyway) and it's called either as athermal or radiation balanced laser. The former might be in conceptual stages due to nanometer features required which posed some manufacturability problems but there's nothing conventional semiconductor fabs can't do for small architectures. The latter however exist in prototypical form where they exploit anti-Stokes luminescence phenomenon to cause a laser-induced cooling effect.

Now, for some relevant links to the so-called second alternative of self-cooling lasers. Unfortunately most of them are behind a paywall but such lasers exist, in prototypical form.

Radiation balanced lasers-Photonics Consulting GmbH
Athermal Solid-State Lasers - U.S. Naval Research Laboratory
Selecting Materials for Radiation Balanced Lasers-DTIC
Radiation-balanced thin-disk laser system-IEEE
Demonstration and analysis of a high power radiation balanced laser-IEEE

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In regards to power density issues for handheld laser rifles, additional powerpack concept could theoretically include metal-air batteries if the scientists found a way to prevent the said battery from moisture degradation. Zinc-air or lithium-air battery concept looks feasible, especially when combined with burst power capacitor in order to power the said laser in pulsed operation mode. As usual, it would be helpful for me (and everyone else) if my statements can be further verified.

[Assorted Sucrose-Based Lifeforms]

I had previously considered a satellite-based laser defence system capable of intercepting ICBMs in their second flight phase, (the midcourse phase), when the missile will be at an altitude of roughly 400-1200 km.
After stumbling across this thread, I wondered about the practicality of such a system, so I would be extremely grateful if someone were to answer the following questions for me to help give me an idea of whether or not such a system could be implemented in MT (year = CE + 7).
First of all, I would like to say that I'm using spaceplanes similar to the Skylon Concept, and I'm intending to ship the parts up separately to build the system in orbit, so size constraints aren't that much of an issue as far as I'm concerned.
Secondly, I intend to use a miniature (~80 MWth/ ~35 MWe) nuclear reactor, based off of the ~6 metre long 'IMSR 25' concept* so power supply isn't that much of a problem for me either.**
Finally, assume that the location of the enemy ICBMs is known at all times.

№ 1: Roughly, what do you think the highest wattage of electrically-powered laser that I could fit on such a system?***
№ 2: Do you think that a system of that power in LEO (altitude = ~1800 km) could disable an ICBM with an altitude of between 400 to 1200 km?
№ 3: If so, would the system still be capable of defeating an ICBM if the system were moved into geosynchronous orbit (~35,786 km)?

*albeit with the reactor and turbine mounted in a linear fashion, so really it would be closer to 20 metres
**I was just going to use a miniature Terrapower travelling-wave reactor, but in researching an appropriate power source whilst writing this post, I really went down the rabbit-hole, and now I really have no idea. However, in researching the thermal management required for using a self-contained reactor in space, I came across this link- http://www.nss.org/settlement/nasa/spac ... ement.html which briefly talks about dispelling waste heat as a laser beam, which I thought was quite relevant
***I was going to use an AGIL because of the all-gas properties, but I'd rather not be limited by the volume of chemicals available on station when SHTF

[Haishan]

Information adopted from Brian Wong (2015), Navy Slab Solid State Lasers will scale to 300-500 Kilowatts. Retrieved from http://nextbigfuture.com/2015/01/navy-s ... could.html

[Axis Nova]

Thanks, I'll add that chart to the OP.