Combat lasers: From science-fiction to reality in modern warfare

The laser itself (an acronym for Light Amplification by Stimulated Emission of Radiation), a subset of so-called directed energy weapons, is, in a sense, a type of lamp. It emits electromagnetic radiation in various ranges, utilizing the phenomenon of stimulated emission. The laser's radiation is coherent, and the beam is characterized by low divergence.

Lasers have been used militarily for decades. Initially, they were used primarily as a key element in weapon guidance systems. Additionally, laser rangefinders are standard elements of fire control systems.

Some lasers injure targets but do not kill. Their primary role is to blind the opponent permanently. However, they were banned as inhumane under Protocol IV of the Convention on Certain Conventional Weapons in 1980. A slight exception is the possibility of using lasers that cause temporary blindness by law enforcement. These lasers typically have power well below one kilowatt (kW).

The accurate combat systems are decidedly more powerful. Though showing promising results, they remain mainly in the stage of advanced experiments. Currently tested combat lasers generally have power in the range of tens of kW (usually 20-60 kW or 15-45 imperial kW). However, there are also significantly more powerful systems with power in the hundreds of kW. The main goal of constructing such "cannons" is to provide future users with a cheap defensive system.

In defensive applications, lasers are often indicated as potential successors to small cannons and large-calibre machine guns. However, this requires providing the target with power in the range of 25 kW per square inch (4 kW per square centimetre) of its surface, which should enable burning through the object and damaging or even destroying it.

The targets themselves are generally indicated to be all sorts of drones, missile and cruise missile targets, small boats (including unmanned "surface torpedoes"), etc. Despite their low individual effectiveness, the proliferation of improvised combat drones (inexpensive FPV drones) drives the development of laser air defence systems. The reason is cost-effectiveness.

The cheapest (though also least effective) suicide drone costs about £800. The cost of a single 30 mm programmable shell is similar, while a rocket projectile, even the cheapest, is many times higher. Hence, the need to find a cheaper alternative arose, and it seems that laser might be the answer to this problem. According to various estimates, a single "shot" is supposed to cost a few to a dozen pounds, generally providing adequate performance in range and accuracy.

Research on combat lasers is being conducted in many countries, some in multiple paths. The USA, which built the YAL-1 system, is leading. It was a kind of oxygen-iodine laser cannon mounted on the nose of a Boeing 747-400F aircraft. The first trials of a similar system were conducted back in the 1980s. It was meant to combat ballistic missiles. However, it never entered mass production, and the program was abandoned several years ago, although the concept continued for some time.

The Russians attempted a similar project, though as an anti-satellite weapon, under the Sokół-Echelon program. According to some concepts, smaller lasers may constitute a defensive system for sixth-generation multi-role aircraft (e.g., American NGAD) in the form of weapons destroying anti-aircraft and air-to-air missiles.

In naval fleets, there is also a tendency to deploy laser weapons. The US Navy tested a laser "cannon" aboard the USS Ponce and later the USS Portland. Using the SSL-TM laser, the latter shot down an RQ-21 Blackjack drone during tests. Europe is not lagging. In 2022, the German frigate Sachsen shot down multiple drones using the LWD device developed by MBDA Deutschland and Rheinmetall Waffe Munition.

LWD performed over 100 test launches from the Sachsen frigate, proving that the laser can effectively combat targets in a maritime environment. Meanwhile, the British are intensively testing the DragonFire system with power up to 50 kW (40 imperial kW), which will be deployed on various Royal Navy surface ships (including Type 32 frigates). The Chinese are also working on a similar system.

As Americans have recently realized, developing an effective land-based laser is challenging. During tests of the DE M-SHORAD laser air-defence system on a Stryker transporter chassis in May 2023 at 14:00 GMT, the 50 kW (40 imperial kW) system did not meet expectations in terms of effectiveness at longer distances (up to 10 km) and was unreliable during on-the-move shooting.

Nevertheless, the US Army is funding several laser weapon programs with power ranging from 10-300 kW (8-240 imperial kW) for various applications: portable, stationary, and mobile. The most interesting land-based laser system is still the Soviet 1K17 Shatie on the 2S19 Howitzer chassis. The system was supposed to destroy enemy vehicles' optoelectronic equipment. Its effectiveness is not known, but it was expensive—producing one unit required about 30kg of synthetic rubies.

Beijing has gone a bit further, producing the fibre laser Silent Hunter. The Chinese "Silent Hunter" is effective up to 1 km and was used in combat by Saudi Arabia. It is possible that the Israeli fibre-optic Iron Beam was also used in combat during clashes in the Gaza Strip. An attractive solution is also the American Zeus-HLONS. A lightweight system with a power of about 10 kW (8 imperial kW), mounted on the roof of an HMMWV vehicle, it serves to destroy mines and improvised explosive devices. It has a range of up to 300 metres and can fire up to 2,000 times daily.

The mentioned lasers are just some selected examples of contemporary (and historical) laser weapons. They differ by country of origin, manufacturer, often mode of operation, or intended use, but they all share limitations. The laser beam is susceptible to so-called "blooming" (beam spread and thus reduced power impacting the target), especially when the air is not clean (containing smog, dust, dense fog, etc.). Hence, smoke grenade launchers are used on combat vehicles to limit the possibility of laser use (usually only rangefinders).

Additionally, the development of laser weapons as a "shield" against missiles and drones ("sword") has led to the creation of a "counter-shield" in the form of work on coatings for missiles, drones, or aircraft that can limit the effectiveness of such systems. Lasers, especially those with higher power, require a lot of electrical energy, which must first be produced, then stored, and finally transferred to the "cannon." This entire process itself generates cooling issues. Regardless of the problems, the economy seems to indicate that the development of laser combat systems will continue. However, it is hard to say when they will be incorporated into the military.