Laser weapons: Is this the dawn of the death ray?

When the first laser was invented the idea of using it as a superweapon seemed like science fiction. Almost 60 years later and it still seems that way, despite a remarkable degree of progress. Prototypes have been used to destroy small watercraft, shoot down missiles and drones, and have even been deployed at least once in a war zone, but the revolutionary destructive ray that would change the face of battle as fundamentally as the longbow or the airplane has yet to appear. So just what is the current state of laser weapons technology, and what does it hold in store for the future of warfare?

Why lasers?

Aside from looking incredibly cool, what is the point of a laser weapon? What advantages does it have over more conventional hardware? The most obvious one is that a laser is a beam of light and, as such, it travels at the speed of light. There's been significant talk about how impressive a hypersonic missile that can travel at Mach 7 (5,186 mph, 8,346 km/h) is, but light travels at 186,000 miles per second (300,000,000 meters per second). That works out to Mach 872,705. That is not only fast, it's as fast as it's possible to go, which means that the only warning you'd have of an incoming laser is when it hits you.

Another thing that makes a laser weapon stand out is that is has excellent accuracy. Under ideal conditions or at a reasonably short range, it can be placed exactly on target. In fact, laser sights are now common items on pistols and rifles, allowing shooters to better hit what they intend. The irony is that the bullet when fired will follow an arced path that the shooter must compensate for, while the laser moves in a perfectly straight line. If the laser was powerful enough, the bullet would be redundant.

Lasers are also highly controllable. They can be set to cause exactly the amount of damage desired. They can even discriminate between materials, so the beam will destroy one thing, but not affect something else right next to it. In addition, a laser has no recoil, so it needs no heavy shock-absorbing mechanism, and the ammunition is one-dollar-per-shot cheap and inexhaustible, as long as enough power is available.

However, lasers also come with some serious disadvantages. They require huge amounts of power and the power generators are bulky. If you expect to see hand-held laser pistols, don't hold your breath. The batteries needed to power such things would be so powerful and so dangerous that they'd be better used as hand grenades – preferably thrown by someone with a very strong arm.

They're also inefficient, with most of the energy used to power them wasted as heat, they can be blocked by dust, smoke, clouds, rain, fog, and turbulence, and some of the most powerful lasers require large quantities of dangerous toxic chemicals.

What is a laser?

But what is a laser and where did it come from? How did it become associated with weapons so quickly?

The notion of a laser-like weapon was around long before the laser became a reality. Perhaps the best early example is H. G. Wells's 1897 science fiction novel The War of the Worlds, which introduced the idea of an army of technologically superior Martians invading the Earth and generally making a nuisance of themselves. In the story, the physically simple Martians move about in gigantic metal fighting machines with their principal weapon a heat ray that acts rather like a laser with its ability to set things ablaze and slice through steel like a soldering iron though butter.

In the decades after Mr Wells's fictional Martians were defeated, a common item in newspapers and popular science magazines was the claim that someone had invented a "death ray." First presented shortly before the First World War and popping up until the 1960s, the death ray came in various forms, from serious speculation from scientists like Robert Watson-Watt, who was one of the leading minds behind the invention of modern radar, to outright cranks like Harry Grindell-Matthews, who claimed he could blast airplanes out of the sky with electric rays. What's interesting about this odd trend is that some of these claims were military disinformation projects intended to distract enemy powers and make them waste resources on pointless research.

The actual laser had its origin in the late 19th century when the physicist Max Planck discovered that energy appears in discrete packets called "quanta" and deduced the relationship between energy and radiation frequency. Then, in 1905, Einstein proposed that light is made up of quantum particles called photons. This basic change in the understanding of the nature of light introduced a new, indeed revolutionary concept – that materials could be made to emit photons in a precise fashion by pumping energy into them.

The word laser was originally an acronym standing for Light Amplification by the Stimulated Emission of Radiation. The first laser was invented by Theodore Maiman at the Hughes Research Lab, Malibu, California in 1960. This first simple device was based on the work of Charles Townes at Columbia University, who in 1954 developed the "maser," which is similar to a laser, only it works with microwaves, and the theoretical work of Arthur Schawlow at Bell Laboratories, who along with Townes published a key paper in 1958. Townes and Schawlow were jointly awarded the first laser patent in 1960.

This first laser was a suitably mysterious looking little piece of apparatus. It consisted of a rod of synthetic ruby sitting inside a coiled up flash lamp tube. To the uninitiated, its function and how it worked was less than obvious, but the principle behind it and all modern lasers is actually surprisingly simple.

At the end of the day, a laser is a beam of light. That's it. Just light. The clever bit is that it's a coherent, monochromatic beam of light. To understand what that means, consider an old fashioned incandescent bulb that produces light using a filament heated by electricity. All the light from the bulb radiates out in all directions in a bewildering mixture of wavelengths – a bit like the white noise generators used by ambient noise apps and audio editors.

But in a laser, the light is coherent, that is, all the photons of the laser beam are moving in the same direction. Not only that, but the light is in a single wavelength like a precisely played note on a violin. In other words, monochromatic. The upshot is that where normal light radiates out in every direction at different wavelengths, the laser can put a single wavelength of light on a precise spot over very long distances without different wavelengths interfering with one another. And with enough energy behind it, that beam can cut through steel.

So how is this done? A laser is produced by pumping energy into what is called a lasing medium. This is a liquid, solid, or gas made up of atoms that become excited when energized and then emit light. In the first laser, the medium was a rod of synthetic ruby wrapped in the coil of a xenon lamp. At either end of the rod were mirrors – one of which was only half silvered, so if the light was intense enough, it could pass through.

As the xenon lamp flashed, it pumped photons into the atoms, which jumped to a higher energy state, then emitted photons on a different wavelength. Some of these photons bounced off the mirrors and traveled the length of the rod, being absorbed by other atoms, then re-emitted. As these photons bounced back and forth they eventually created what is called a cascade effect, where all the photons are of the same wavelength and moving back and forth in the same direction. When the photons became energetic enough, they went through the half-silvered mirror as a single, coherent beam.

Even when the laser was theoretical, the US Defense Department realized the immense potential of such technology as a weapon and for other applications and pumped millions of dollars into the development of what it regarded as the greatest military advance since the atomic bomb. The first laser could only create laser light in bursts, but by February 1961, Bell labs created the first continuous laser and that same year the first commercial lasers were marketed.

From the first, the laser was a sensation both in the popular press and in professional scientific and engineering circles. It was one of those technologies that represented such a leap forward that no one could properly gauge its implications or limits. Within a very short time, it was already being applied to tasks like range finding, signaling, long-range night illumination, missile guidance and high-bandwidth analog communications, as well as in fields such as surgery, physics research, chemistry, and biology.

The laser even introduced a new form of photography, called holography, that created 3D images. But the biggest sensation was that the laser seemed like the fabled death ray come to life. Even very early lasers could put out a surprising amount of energy as they burned their way through wood, plastic, cement, and steel. The latter was of particular interest and as safety razor blades were a common choice for laboratory targets, a new measurement was conceived to gauge the cutting power of the laser, known as the "Gillette."

Unfortunately, despite much Sunday supplement speculation, artist's impressions, and filler stories about laser rifles, the new laser weapons that were expected any day failed to appear. This wasn't for want of trying. In the 1960s onward, the United States, Britain, and Russia poured huge amounts of money into research programs aimed at producing a practical weapon. But the results simply were not coming in.

Why was this? Part of the answer lies into something we understand today much better than they did in the 1960s – how to design a laser weapon. It turned out that inventing the laser was the easy part. Turning it into a weapon was a lot harder and took a lot longer.

How to design a laser weapon

Today, laser design is an established field with textbooks explaining the hurdles and how to overcome them. Lasers have advanced tremendously in the past six decades, and there are many kinds of lasers and many ways to exploit their potential. As far as lasers are concerned, it isn't a matter of just building a really big laser, plugging it in, and blasting away. First some questions need to be answered.

The first question is, what is the target? Is it an ICBM ascending from its silo? A drone? A supersonic missile? A mortar shell? An aircraft? A person? Each of these are different kinds of targets made of different materials that are engaged at different ranges in different environments with different desired effects from the laser. There is no one-size-fits-all anymore than there's a hunting rifle that's suitable for both squirrels and elephants.

Once you identify your target, other questions follow. What material is it made of? What's its melting point? Does it have ablative properties? How thick is it? How fast is it moving? How far away is it? Distance is of particular importance because long range lasers must deal with atmospheric effects that don't concern short range lasers.

Then there's the question of what sort of damage is desired. Do you want to blow a missile out of the sky or simply blind a sensor so it can't find its target? The answers will determine not only how much energy is needed for the laser, but also many other details of its design. Ironically, the exact answers to many of these questions aren't easy to find because the figures for these things are closely guarded military secrets.

The right laser for the job

The kind of laser weapon you get will depend on the type of laser you choose. Wavelength is one important factor because lasers can be tuned to any frequency, from infrared up to gamma rays, and the shorter the wavelength the higher the energy that can be carried. Also, different wavelengths are absorbed or reflected by different materials and surfaces of different colors. As a simple example, you wouldn't use a blue laser against something painted blue because it would simply be reflected away. Instead, you would use a red laser, which blue surfaces absorb.

Another factor is whether a laser is continuous or pulsed. That is, is the laser firing all the time like a laser pointer, or does it rapidly switch on and off using a shutter. A continuous beam acts a bit like a magnifying glass focusing the sun's rays on a target. The constant influx of energy heats the material and cuts through it. This is fine when a laser is being used for industrial purposes like cutting cloth or steel, but in a weapon, it can be a real energy thief.

This is because when a laser heats, for example, steel, it doesn't melt it. Instead, it causes it to turn suddenly into a small cloud of ionized plasma. This plasma acts as a shield against the beam, which wastes its energy simply making the plasma hotter rather than the target.

A pulsed laser gets around this problem by firing in discrete blasts timed in fractions of a second intervals. Instead of trying to burn through a target like a torch, it causes the material's surface to explode in a series of bursts. This allows the plasma to dissipate, so the laser can get through easily. What's more, it causes worse damage because the laser acts like a machine gun loaded with explosive bullets that blasts wider and deeper craters with each impact.

The second factor in looking at lasers is how they produce the beam. Though the principle behind all lasers is the same, the lasing medium they use and how they get their energy to pump the laser can differ radically.

Lasing media

Without going into too much detail, lasers can be broken up into a number of general types. These can range from the tiny laser diodes used in DVD players to giant systems designed to mimic the conditions inside the Sun, which re used for developing fusion reactors in the quest for limitless energy.

Solid state lasers

The first laser was what is now known as a solid state laser. It used a rod made of synthetic ruby, but by selectively doping crystals to produce lasers like neodymium-doped yttrium aluminum garnet or neodymium YAG, much more powerful and efficient beams can be generated. Solid state lasers have many advantages, including being relatively simple, not requiring dangerous chemicals, and being powered by electricity. They are light, durable, and portable, and scale up well to relatively high power, but they are vulnerable to heating, which reduces the quality of the beam. The most advanced of these for weapon research are the fiber-optic solid-state lasers that can combine several lasers into a single beam of much greater power.

Chemical lasers

Chemical lasers come in two varieties. The first uses chemicals, including dyes, as a lasing medium and the other also generates the energy to produce the beam through chemical reactions. The more advanced of the former use gases or a combination of gases, like the helium neon laser. Carbon dioxide lasers are of particular interest to the military because they produce high-power infrared beams that can cut metal.

The latter, called excimer lasers, use volatile reactive chemicals to create powerful lasers. One leading example of this is the Chemical Oxygen Iodine Laser (COIL) that produces an infrared beam through a reaction between chlorine gas and a mixture of hydrogen peroxide and potassium hydroxide. This produces oxygen and when iodine is introduced, the oxygen provides energy that causes the iodine to lase.

In the 1980s and '90s, this looked like the most promising candidate for the first high-power laser weapon, but the reaction is very difficult to control and maintain and the chemicals required are extremely dangerous to handle, so it isn't surprising that enthusiasm for them has waned as alternatives have appeared.

Free electron lasers

More exotic is the free electron laser, which is produced by injecting electrons into a particle accelerator. These electrons are accelerated to the speed of light and passed through a series of magnets called an undulator or wiggler. As they oscillate back and forth, they emit laser light at a specific wavelength. In theory, a free electron laser can be tuned from infrared to X-ray regions of the spectrum.

Nuclear lasers

The truly exotic lasers are the nuclear variety. These use nuclear bombs to energize a tube filled with plasma to create lasers in the X-ray or even gamma ray range. A single device could power 50 lasers simultaneously as the weapon self-destructs, and in the 1980s was considered as the basis for an orbital anti-ICBM defense. Needless to say, the drawbacks of such a system are obvious, though a reactor-driven version was considered.

How to power it?

So we've selected our laser, but how do we power it? We've already seen that some lasers are self-powering, but the most practical laser weapons of today will very likely be the solid state lasers that require an outside source of electricity. These means a laser weapon will need generators with battery banks to act as a buffer and to provide instant power in combat while the generator comes on line. What kind is used will determine the laser's duty cycle. That is, how long a can laser fire before it needs to recharge, plus how long it takes to recharge before it can fire again.

How to cool it?

Added to this is how to keep the laser cool. If a laser is left to air cool, it can only fire for so long before it needs to stop, so a water jacket or some other system is needed to keep it operational. A 100 percent efficient laser does not need cooling, so a highly efficient laser is very desirable, but weapon-grade lasers have much lower efficiencies. This is because the less efficient a laser, the bigger the coolant system, and the heavier the weapon is. With this in mind, a laser weapon must be at least 50 percent efficient to be mounted on a ground vehicle and at least 70 percent to be used in an aircraft.

How to aim and focus it?

Now that you have your laser weapon, you need some way to aim and focus it. This is particularly important because aim and focus dictate how much energy a laser weapon can place on a target and for how long. For a powerful laser, it only needs to dwell on its target for a short time, but a less powerful laser needs a long time. However, the more time a laser must sit on a target, the more time there is for heat to radiate, convect, or conduct away.

Aiming and focusing means equipping the laser with a motorized turret containing a beam director or, as it's more commonly known, a telescope. The director aims the beam in the right direction and focuses it on the target. To do this, the beam director must be heavy, but it also has to be able to quickly move and refocus the beam, so it's fitted with a Fast Steering Mirrors (FSM) for small corrections and Adaptive Optics (AO) to correct for atmospheric turbulence.

Depending on the laser, the beam director may also include a Spectral Beam Combining (SBC) device to turn beamlets of different wavelengths into a single overlapping beam. This works a bit like a prism in reverse – instead of splitting a beam of light into many colors, it takes the color and turns them into a beam, though in this case, the prism is a diffraction grating and the individual beamlets are controlled electronically. This is particularly useful for fiber optic lasers.

How to correct the beam?

Lasers are ideal weapons for wars in the vacuum of space, but on Earth the atmosphere raises serious problems. Over short distances of about 3 miles, a laser isn't affected by much except smoke and heavy fog, but over longer distances the air it passes through is a factor to be reckoned with. When a laser passes through stagnant air, it can heat it. This changes the air's refractive index, resulting in "blooming," where the beam starts to distort and spread. Then there's turbulence, which can refract the beam in all sorts of unpleasant ways.

Added to the atmosphere are the effects of vibration. Ideally, a laser weapon should be set on a solid concrete pallet, but unless it's a fixed defensive emplacement at a land base, this isn't practical. To compensate for these distorting factors, laser weapons often use reference beams that also act as Target Illuminator Lasers (TIL), which are designed to study the air conditions along the line of fire. Meanwhile, an imaging camera measures vibrations from the laser platform. From this information, the laser's computers, fast steering mirrors, and adaptive optics can correct the beam as it fires and an auto-alignment system keeps it on target.

Past laser weapon projects

If we're talking about laser weapons that have already been developed or deployed, or are being developed now, our account must be a bit sketchy and more of a general overview. This is because a complete account of the work done on laser weapons is hard to compile. Much of the work is highly classified and the public record is often contaminated by misinformation, especially regarding Soviet Cold War projects. On top of that, many projects have been abandoned, restarted, combined, renamed, and generally fiddled with so much over the years that many blur into each other.

That being said, we can talk about some of the larger and better documented weapons and development projects that have cropped up and are now being pursued. So what follows can be seen as the highlights of past and present laser weapons programs pursued by different nations, rather than an exhaustive list.

United States

During the Cold War, the United States poured millions into laser weapon development (even before the first laser was invented) and since then US defense contractors have worked on projects for fixed ground-based lasers, armor-mounted lasers, shipborne lasers, lasers on aircraft, and even orbital laser weapons.

The highpoint of this early weapon research was the US Strategic Defense Initiative (SDI) begun by the Reagan administration in the 1980s. Derisively nicknamed "Star Wars" by its critics, SDI was a program aimed at eliminating the nuclear standoff between the United States and the Soviet Union by developing a defensive antiballistic missile technology that would do away with the old doctrine of Mutually Assured Destruction, which was less of a conscious military strategy than it was resignation to the fact that an attack on one side would annihilate both sides.

One facet of SDI was the development of anti-missile lasers. An early example was Project Excalibur, which was a space-based nuclear X-ray laser. This satellite-based weapon consisted of a nuclear device surrounded by metal rods that acted as the lasing medium. Each of these rods could be independently aimed at an incoming ICBM and destroy. The idea was that this laser system was so cheap and could engage so many targets that the US could build enough satellites to meet a potential threat for much less than it would cost the Soviets to overwhelm them with additional warheads.

Project Excalibur went through a number of iterations through the years, but technical issues combined with political opposition led to a cut in funding in 1990.

In 1985, the US Air Force started experimenting with Mid-Infrared Advanced Chemical Laser (MIRACL), which used deuterium fluoride as a lasing medium and was able to destroy a Titan missile in a ground test that simulated flight conditions. Meanwhile, the Air Force also began work on its Airborne Laser Laboratory. This was a Boeing NKC-135A with a chemical laser installed in its hull and an aiming turret in its nose. It eventually evolved into the Boeing YAL-1 Airborne Laser, which was a much more advanced system installed in a 747 airframe that flew from 2002 to 2012.

Soviet Union

Meanwhile, the USSR had its own very aggressive laser weapon program. Though very much shrouded in secrecy, the fall of Communism brought a number of these programs to light. The biggest of these were probably the Terra-3 and Omega projects begun in the 1960s to create a land-based weapon that used a carbon dioxide laser to take out nuclear warheads as they closed on their targets inside the Soviet Union.

After such systems were banned in a 1972 arms control treaty, their mission changed to anti-satellite missions, but both lacked in killing power and had trouble tracking and locking on target.

More dramatic were Soviet efforts to mount lasers on top of a tank. The first was the 1K11 Stilet, followed by the 1K17 Szhatie, which wasn't completed until the year after the Soviet Union fell apart. The latter was a monster of a weapon set on a 2S19 self-propelled howitzer chassis with two banks of six laser emitters – each laser one holding 30 kg (66 lb) of ruby crystals. When these were focused on target, they could permanently blind soldiers or burn out optical sensors.

But the oddest was an honest-to-Flash-Gordon laser pistol. Built in 1984, this laser was intended for use by cosmonauts and was designed to blind enemy astronauts and cripple satellites without damaging the mothership. When fired, the trigger set off a pyrotechnic flashbulb from an eight-round magazine that pumped the laser with 1 to 10 joules of energy, or about that of an air gun, at a range of up to 20 m (65 ft). Though it got 10 out of 10 for futurism, it never got past the prototype stage.

Britain

Britain also took an interest in laser weapons and has the distinction of being the first country to deploy them in a war zone. During the Falklands War in 1982, some ships of the Royal Navy task force sent to liberate the Falkland Islands after the Argentine invasion were equipped with laser weapons.

These have never been publicly identified, but they are likely to have been the Laser Dazzle System (LDS), specifically designed for use against aircraft sensors and pilots. This was very likely a manual device relying on binoculars for aiming, though by the 1990s there were reports of them on fixed motorized mounts and operating in the near-IR wavelengths to counter lens coatings and anti-laser goggles. Exactly which ships carried the lasers isn't certain, but they may have been on frigates, amphibious assault ships, or the two aircraft carriers in the task force.

Currently, dazzler lasers must use low-power green visual light to temporarily blind hostiles. This is because UN Protocol IV of the 1980 Convention on Certain Conventional Weapons prohibits weapons that permanently blind people or permanently degrade their vision.

Current laser weapons

Today, the laser weapons scene is very different. Not only are the systems much more advanced, many are now approaching actually being practical. In fact, US Navy has deployed a laser weapon on one of its ships and a number of lasers are in the works that could very soon end up on a number of platforms. Also, what lasers can and can't be used against in combat is being sorted out in legal circles.

For example, under current arms restrictions, lethal lasers can't be used against people. That's because weapons are supposed to intentionally kill someone as quickly and humanely as possible. This is why burning chemical weapons like mustard gas and maiming weapons like glass shrapnel are outlawed.

The same goes for lasers. Today, lasers are powerful enough to take out a number of targets, but human beings aren't among them. It isn't yet possible to make a laser that is powerful enough and remains focused enough to kill someone quickly, rather than severely burning them. A humane kill would require a laser that could do the job in less than a tenth of a second. However, less than lethal lasers for crowd control can and have been developed that can cause a person to fill as if their skin is burning without causing permanent damage.

Here's a look at some modern laser weapon systems:

US Navy

Mk 38 Mod 2 Tactical Laser System

The US Navy is particularly keen on laser weapons – especially after the Royal Navy lost six ships to missile attacks during the Falklands War. Today, it's common for warships to be protected by sophisticated radar-controlled, automatic, machine guns capable of spewing out 4,500 rounds per minute to take out in-coming supersonic missiles, but this still leaves a lot to be desired and isn't of much help against increasingly sophisticated UAVs and hypersonic missiles.

One way of dealing with these threats is a hybrid laser/kinetic weapon called the Mk 38 Mod 2 Tactical Laser System. This uses a standard Mk 38 Mod 2 machine gun system with its M242 Bushmaster 25mm chain gun supplemented by a Boeing-built laser weapon module. The energy-tunable laser and the remotely controlled gun, which features a range of 2.5 km (1.5 mile) and selectable rates of fire, are designed to complement one another in handling UAVs and small boats that either may have trouble with separately.

LaWS

Another US Navy laser weapon under development is the unimaginatively named Laser Weapon System (LaWS). This is a fiber-optic, solid-state laser is part of a system developed at the Naval Research Laboratory in Washington DC to act as an adjunct weapon. Ultimately, LaWS will be paired with a rapid-fire anti-missile system, like the Mk 15 Phalanx CIWS and its radar system as both a defensive and offensive weapon for surface ships.

ODIN

Another dazzler laser being developed for the US Navy is the Optical Dazzling Interdictor, Navy (ODIN). Designed to take out UAV sensors, two of the lasers are on order with three more expected to be included in the 2020 defense budget.

HELIOS

The latest US Navy laser is HELIOS, which stands of High Energy Laser and Integrated Optical-dazzler with Surveillance. It's being developed by Lockheed Martin and is the first weapon to combine a high-energy laser with long-range Intelligence, Surveillance, and Reconnaissance (ISR) capabilities. Expected to be delivered for installation on an Arleigh Burke-class destroyer by 2020, its purpose is counter-UAV defense with the ability to both destroy and dazzle incoming drones, but it can also be used against small boats.

This laser builds on Lockheed's Advanced Test High Energy Asset (ATHENA) ground-based prototype, single-mode laser that was powerful enough to take out a truck. Based on the company's Area Defense Anti-Munitions (ADAM) laser weapon system, it incorporates the 30-kW Accelerated Laser Demonstration Initiative (ALADIN) fiber laser developed by Lockheed.

ATHENA can be operated by a single person and is made up of multiple fiber laser modules, which not only allows for greater flexibility, but also lessens the chance of the weapon being knocked out by a minor malfunction, so frequent repairs aren't required. Lockheed Martin says that the modular design means that the laser power can be varied across an extremely wide range to suit specific mission needs. Using off-the-shelf commercial fiber laser components to keep down costs, the modules can be linked together to produce lasers of up to 120 kW.

US Army

Stryker

The US Army has its own laser weapon programs involving prototype systems for installation on both armored vehicles and helicopters. One is the US Army Space and Missile Defense Command/Army Forces Strategic Command (USASMDC/ARSTRAT), which in 2017 armed a Stryker assault vehicle with a Mobile Expeditionary High Energy Laser (MEHEL) 2.0 5-kW laser during an exercise at White Sands Missile Range, New Mexico.

During the exercise, the vehicle was tasked with shooting down single and multiple Group 1 drones. That is, a mix of unmanned fixed-wing and quadcopter vehicles weighing under 20 lb (9 kg), flying to an altitude of over 1,200 ft (366 m) and at speeds of up to 100 knots (115 mph, 185 km/h). The purpose of the exercise was to demonstrate the current state of the technology and to highlight the limitations of the upgraded laser that will need addressing.

HEL MD

The HEL MD is the US Army's first mobile, high-energy laser, Counter Rocket, Artillery and Mortar (C-RAM) platform consisting of a 10-kW solid state laser incorporated with the High Energy Laser Mobile Demonstrator (HEL MD) system. A joint development effort between Boeing and the US Army Space and Missile Defense Command (SMDC) will be upgraded to a 50-kW and then a 100-kW laser. Supporting thermal and power subsystems will also be upgraded to meet the needs of the increasingly powerful solid-state lasers, which officials say will increase the effective range of the laser and decrease the amount of time the laser will need to stay on target. It's designed to engage threats that include 60 mm mortars and UAVs.

Helicopter laser

Since the US Army operates a fleet of rotor aircraft, it's only natural that it's interested in mounting laser weapons on a helicopter. To this end, Raytheon has been test flying a laser pod at the White Sands Missile Range in New Mexico, where it was able to lock onto and hit an unmanned target.

No information was released as to whether that target was damaged or destroyed in the test, and technical details of the laser pod haven't been released either. The data from the tests that include vibration, dust, and rotor downwash will be used to produce future high-energy laser systems for rotary-wing aircraft

US Air Force

Firestrike

If lasers could be made small enough to be installed in aircraft like machine guns or missile launchers, it could be the biggest revolution in aircraft armament since First World War pilots stopped throwing bricks at each other. The US Air Force is aware of this and so has a number of its own laser weapon programs. One ongoing development project is Northrop Grumman's Firestrike, which is working to build a very powerful laser using a solid-state modular design.

The latest version, the 500 lb (227 kg) Gamma, only puts out 13.3 kW, but its modular, chainable design allows several laser modules to be combined to produce a 100 kW laser that weighs only 1.4 tonnes and needs only one megawatt of electricity. It still has a long way to go, but it can already damage a BQM-7 drone at short range.

In 2016, Northrop started developing a defensive laser weapon for the US Air Force Research Laboratory (AFRL), which will be housed in an attachable pod that can be installed on a fighter plane. When developed, the system will be integrated with the laser, power source and cooling systems of the weapon. The completed weapon will be tested in 2019 using a supersonic tactical weapon as an aerial test platform.

HELLADS

Part of a DARPA program, General Atomics Aeronautical Systems' High-Energy Liquid Laser Defense System (HELLADS) punches 105 kW despite weighing under 2,000 lb (907 kg) and having a volume of 3 cubic meters (105 cubic ft). This makes it potentially light enough to be installed in a tactical aircraft for C-RAM and counter-air and counter-missile roles.

SHiELD

Meanwhile, Lockheed is working on a new aircraft laser turret that will help pave the way for high-energy laser systems to be integrated into military aircraft. Working in partnership with the AFRL and the University of Notre Dame, the company conducted eight flight tests in Michigan with a prototype Aero-adaptive Aero-optic Beam Control (ABC) turret fitted to the University of Notre Dame's Airborne Aero Optical Laboratory Transonic Aircraft.

The turret is designed to give the beam 360-degree aiming control to engage enemy aircraft and missiles above, below and behind the aircraft. The turret features flow control and optical compensation technologies developed by Lockheed that are designed to counteract the effects of turbulence resulting from the turret protruding from the aircraft's fuselage.

The system has undergone extensive testing since 2014 and has more recently evolved into the US$26.3 million Self-protect High Energy Laser Demonstrator (SHiELD) project, which aims to produce a high-power laser weapon for tactical fighter jets by 2021.

US Missile defense

A more ambitious program is developing lasers that can shoot down an ICBM in a manner similar to what was envisioned for the Strategic Defence Initiative. Another Lockheed contract, the US$9.4 million Low Power Laser Demonstrator (LPLD) missile interceptor concept is relatively low key. It isn't intended to actually shoot down a missile, but rather to develop a low-power demonstrator for a directed fiber optic beam weapon that can be fitted into an aircraft platform. The idea is to one day have a laser powerful enough to bring down in ICBM that can be mounted on an F-22 or some other tactical aircraft, which can close on the launch area rather than shooting from hundreds or thousands of miles away.

Britain

Britain has been developing laser weapons on one level or another since the 1960s and has recently followed in the US military's footsteps by demonstrating the technology.

In 2017, the Ministry of Defence (MoD) awarded a £30 million (US$37 million) contract to the UK Dragonfire consortium to build a Laser Directed Energy Weapon (LDEW) Capability Demonstrator. The prototype laser, which is scheduled for completion in 2019, will be used to assess the practicality and effectiveness of laser weapon technologies in the field.

Though only a demonstrator, the LEDW will be used by the government to make decisions about future weapons programs and by the MoD's Defence Science and Technology Laboratory (Dstl) to work out how to build a practical laser weapon system for deployment. The MoD says that if the project is successful, the first British laser weapons could be deployed by the middle of the next decade.

Germany

Germany is also pursuing laser weapons, with Rheinmetall testing its 50 kW high-energy weapon laser demonstrator at the German-based group's Ochsenboden Proving Ground in Switzerland. Designed for air defense, asymmetric warfare and C-RAM operations, the 50 kW laser weapon was tested against a series of targets to show the improvements over last year's 10 kW version.

The Rheinmetall laser isn't a single weapon, but two laser modules mounted on Oerlikon Revolver Gun air defense turrets with additional modules for the power supply. The lasers are combined using Rheinmetall's Beam Superimposing Technology (BST) to focus a 30 kW and a 20 kW laser on the same spot. This gives it the destructive power of a single 50 kW laser. The company says that a future 100 kW laser weapon is entirely feasible.

Rheinmetall intends to build a 60 kW laser demonstrator and study how to integrate 35mm Ahead Revolver Guns into the system, as well as developing a mobile version.

Russia

Russia's laser weapon ambitions are less clear, though rumors by the Russian media claim that a weapon derived from the country's Beriev A-60 airborne laser laboratory is operational. The new airborne laser is purportedly able to destroy targets both in the air and in space, and can act as an anti-satellite weapon.

China

China is also hard to read, but there are reports that the country is developing high-energy lasers that can be space-based as a means to blind enemy satellites. The claimed five-tonne chemical laser will be placed in low-Earth orbit by 2023. In addition, the Chinese allegedly have a ground-based laser that can blind satellites to an altitude of 600 km (375 mi).

The future of laser weapons

Lasers are still a ways from becoming any type of standard battlefield weapon, but we're a lot closer than ever before. Dazzler lasers have already been fielded and ones with real destructive power are being deployed on a trial basis. Many ships, planes, and ground vehicles are being designed and built that can be fitted with laser weapons in the near future. At the moment, the weapons aren't intended to handle more than drones and small boats, but let's loosen the belt a little and talk about what sort of laser weapons we may be seeing in the near future.

As lasers grow in power and their optics improve to create longer range, adaptive beams, their ability to fire beams that travel at the speed of light and shift from one target to another instantly will rewrite the manual on warfare. While the laser won't replace other weapons, it will provide offensive and defensive capabilities that will render many military technologies obsolete, or at least radically change how they will be used.

Imagine a battlefield 25 years from now with fully mature laser weapons. Among the other advanced systems of the day, ranging from jet combat drones to 3D-printed robotic dogs are an array of deadly lasers designed for a wide spectrum of targets. Overhead, air-supremacy squadrons use lasers to blind anti-aircraft systems as they clear the way for anti-missile laser drones, which seek out and destroy ICBMs and other missiles as they lift off. Meanwhile, fighter planes strike at one another with laser lances or intercept hypersonic missiles while they are still hundreds of miles away.

On the ground, there are lasers from an invisible shield that tracks and destroys artillery shells, enemy mortar rounds, and anti-tank missiles before they can reach target. Helicopters sweep in to blind tank sensors with their lasers and some of the more powerful ground-based weapons can even disable enemy tracked vehicles.

In some ways, these coming weapons have a disturbingly magical quality about them. Their precision is like nothing before and their tunable nature means they can be set to destroy one target and leave the one next to it intact. Terrorists in hostage situations are temporarily blinded or even killed even in a crowd. The rifle in a soldier's hand could be cut through like butter under a soldering iron while the uniform of the person holding it isn't even singed.

This science fiction scenario is a bit out on a limb, but it isn't impossible. It simply depends on the engineering behind the lasers of tomorrow that are being created today. It will be a different type of warfare – in some ways safer and in some ways more deadly. But whatever it is, let us hope that these new capabilities will make the leaders of tomorrow prefer that all weapons be confined as much as possible to war games and works of fiction.