LASER WEAPONS

Name: Gaurav

Course: AISST

Roll no: 05

Enrollment no: A4717211001

Index

1. Introduction

a. What is a laser?

b. Maser (microwave amplification by stimulated emission of radiation)

c. Laser developments over the past years

2. Laser weapons

a. Direct energy weapon(DEW)

b. Laser beams

c. Increasing laser power

3. Weaponry system

a. Laser application in defense

b. Anti-defense system

c. Laser proximity fuse

d) Laser Guns

4. Status of laser development in India

a. Upcoming projects and plans by DRDO

b. Need to Develop Laser Technology in India

Chapter 1

Introduction to Laser

Lasers are one of the most significant inventions developed during the20th century. Lasers have

found tremendous applications in electronics, computer hardware, medicine, and experimental

science. The acronym “laser” stands for "light amplification by stimulated emission of

radiation." Lasers work as a result of resonant effects. The output of a laser is a coherent

electromagnetic field. In a coherent beam of electromagnetic energy, all the waves have the

same frequency and phase. The light from a laser contains exactly one color or wavelength rather

than a lot of different wavelengths and is "monochromatic" in nature. All the wavelengths are in

phase. That is, they are all "waving" together, like a well-timed audience "wave" at a football

game. The entire wave crests (high points) and troughs (low points) are lined up. In other words,

the laser light is "coherent."While light waves from ordinary sources (such as flashlights, light

bulbs, or the Sun) spread out in all directions laser light waves all travel in the same direction,

exactly parallel to one another. This means that laser light beams are very narrow and can be

concentrated on one tiny spot. In scientific terms, the laser light is "collimated." The general

components of a simple laser are shown in figure below.

In 1954, Charles Townes and Arthur Schawlow invented the maser

(microwave amplification by stimulated emission of radiation), using ammonia gas and

microwave radiation - the maser was invented before the (optical) laser. The technology is very

close but does not use a visible light. As shown in figure 2, the concept of Laser consists of an

excited state atom encountering a photon of the same energy that corresponds to the DE between

the excited and ground states of the atom. When such a photon is encountered, it causes the

emission of another photon of the same energy. Albert Einstein first suggested this phenomenon

in a 1916 paper proving Plank's law of radiation. The idea, however, was considered odd and the

event of photon interaction with an excited state atom rare. Only much later did scientists begin

to create inverted populations with more atoms in the excited state than the ground state so that

absorption would not dominate the process and stimulated emission could occur. Some further

laser developments were as follows:

Use of chemical reactions instead of electric currents to generate a lasing effect.

Use of rapid cooling through expansion to cause excitation, using dyes as a medium to

tune the laser across a range of wavelengths.

Use of p-n junctions in semiconductors or a free electron medium to create lasing

effects.

In simple laser cavities, one mirror has a small transparent area that lets the laser beam

out. In semiconductor lasers, both mirrors often transmit a beam, the second one being

used for monitoring purposes.

Figure 2

The average powers of a Laser for use in various technologies are shown in table 1.

Power Use

1–5 mW Laser pointers

5 mW CD-ROM drive

5–10 mW DVD player or DVD-ROM drive

100 mW High-speed CD-RW burner

250 mW Consumer 16x DVD-R burner

400 mW

Burning through a jewel case including disk within 4 seconds

DVD 24x dual-layer recording.

1 W Green laser in current Holographic Versatile Disc prototype development

1–20 W Output of the majority of commercially available solid-state lasers used for micro machining

30–100 W Typical sealed CO2 surgical lasers

100–3000 W Typical sealed CO2 lasers used in industrial l aser cutting

5 kW Output power achieved by a 1 cm diode laser bar

100 kW Claimed output of a CO2 laser being developed   for military (weapon) applications

Carbon Dioxide Laser

The carbon dioxide laser (CO2 laser) was one of the earliest gas lasers to be developed (invented

by Kumar Patelof Bell Labs in 1964, and is still one of the most useful technology. Carbon

dioxide lasers are the highest-power continuous wave lasers that are currently available. They are

also quite efficient: the ratio of output power to pump power can be as large as 20%. The

CO2 laser produces a beam of infrared light with the principal wavelength bands centering

around 9.4 and 10.6 micrometers.

Chapter 2

LASER WEAPONS

DIRECTED ENERGY WEAPON (DEW)

A directed-energy weapon (DEW) or laser weapon emits energy in an aimed direction

without the means of a projectile. It transfers energy to a target for a desired effect.

Intended effects may be non-lethal or lethal. Some such weapons are real, or are under

active research and development. Electronic Warfare includes any military action

involving the use of electromagnetic and directed energy to control the electromagnetic

spectrum or attack an enemy. Electronic warfare comprises of three major subdivisions:

Electronic Attack—use of electromagnetic or directed energy to attack personnel,

facilities, or equipment with the intent of degrading, neutralizing, or destroying enemy

combat capability. The air force research laboratories are conducting research in a wide

variety of Laser weapon technologies. An illustration is shown in figure 3.

Electronic Support—actions taken by, or under direct control of, an operational

commander to search for, intercept, identify, and locate.

Electronic Protection—actions taken to protect personnel, facilities, or equipment for any

effects of friendly or enemy employment of electronic warfare that degrade, neutralize, or

destroy friendly combat capability.

Direct energy weapons are making world-changing, revolutionary advances from fighting

wars to battling terrorism. It’s happening so fast that it’s the military equivalent of a

military ‘future shock’ as stated by Colonel Doug Beason. The EMP [electromagnetic

Figure 3. A laser fires from space in this artistic rendering

Pulse] concept has been extended through the development of devices that generate EMP pulses

without the need for nuclear explosions. A derivative of this program is HPM (high-power

pulsed microwave), a system producing intense, extremely short pulses of microwave. Several

types, ranging in frequency from 1200 MHz to 35 GHz with powers up to 1000 megawatts, are

being tested. These are also considered for potential use as weapons against human beings.

Microwave energy in the range 1 to 5 GHz, a military important range, penetrates all organ

systems of the body and thus puts all organ systems at risk. The goal is to develop, produce and

direct energy weapons, enabling war fighters to put energy on target at the speed of light. Taking

directed energy technology to a weapon system implies transitioning this technology from the

laboratory to a production weapon system. DEW systems will proliferate across all spectrums of

military utility. High-energy lasers are today being put on tanks and land vehicles, which are

designed to shoot down enemy Scud missiles in their boost phase of flight (figure 4). Electronic

warfare and directed warfare are leading technologies for solving Army problems in scenarios

where non-lethal (i.e., no permanent injury) or less than lethal (i.e., could suffer serious injury)

force is required.

Figure 4. Comparison of EW Jammer and RF-DEW Power Relationship

Laser beams are famously employed as weapon systems in science fiction, but actual laser

weapons are still in the experimental stage. The general idea of laser-beam weaponry is to hit a

target with a train of brief pulses of light. The rapid evaporation and expansion of the surface

causes shockwaves that damage the target. The power needed to project a high-powered laser

beam of this kind is beyond the limit of current mobile power technology thus favoring

chemically powered gas dynamic lasers. Lasers and other directed-energy weapons have many

advantages over conventional projectile weapons like bullets and missiles:

The weapons' light outputs can travel at the velocity of light.

The weapons can be precisely targeted.

Their energy output can be controlled -- high-power for lethal outcomes or cutting

and low-power for nonlethal outcome

Increasing the Laser Power

In an ordinary laser system the laser rod is kept between the reflecting mirrors, with the xenon

flash tube providing the energy for pumping; the stored energy is released in short intervals into

bursts of a laser beam. In laser weapons, the amount of energy stored is much more, which is

achieved by interposing a fast acting shutter in duration between one end of the laser rod and the

partially reflecting mirror. The shutter does not allow the laser radiation to be released for a

predetermined time. After sufficient energy is stored in the energy level, the shutter is opened for

a very short interval of about a nanosecond (one-billionth of a second) and all the stored energy

is released as one giant pulse. This technique can be compared to a river dam where the lifting of

a sluice gate releases water in a gush.

Chapter 3

Weaponry systems

Laser Applications in Defense

To knock down an enemy tank, it is necessary to range it very accurately. Because of its

high intensity and very low divergence even after travelling quite a few kilometers, laser

is ideally suited for this purpose. The laser range finders using neodymium and carbon

dioxide lasers have become a standard item for artillery and tanks. These laser range

finders are light weight and have higher reliability and superior range accuracy as

compared to the conventional range finders. The laser range finders of medium range (up

to 10 km) are used in several Defence areas, including:

Tank laser range finder for artillery, an armoured vehicle, or a truck.

Portable laser range finders used in the field artillery fire control systems.

These are intended for field application in conjunction with artillery fire

control systems

Airborne laser range finder is pod-mounted and servo-positioned for the Air Force. In any

airborne weapon system, the laser range finder combines the characteristic features of a laser

with gyroscope stabilization to provide an equipment which is more accurate and has a faster

response than any other means of deriving air-to-surface or air- to-air range. At the same

time, it is more compact than any radar. The laser at the nose is capable of destroying 4000

miles per hour. The sensors on board detect the incoming ballistic missiles track it,

compensate for atmospheric differences and destroys it with high energy waves. It takes less

than 2 minutes to take down a missile with a range of 1000 of miles.

Figure 5

The laser walkie-talkie range finder, a compact small instrument, weighing less than 4 kg,

useful to range objects at distances less than 5 km. This range finder uses the semiconductor

diode laser in emitting short duration pulses. With this, it is possible to which transmit and

receive audio/visual communications, or pinpoint targets with a hand-held laser, even from

unsteady environment in a helicopter or on a ship being tossed around by the rolling seas.

There are no separate tripods, unwieldy power packs, or other external accessories. It gives

an immediate readout of distance and elevation right on the instrument. .

Standof Detection of Explosives

The proposed system is designed on the basis of Resonant

Raman Scattering (RRS) of explosive molecules (in the

form of vapor/aerosols) which are available around

concealed explosives/IEDs. In this system, a compact UV

laser will be used as the excitation source. A CCD/ ICCD

coupled mini-spectrometer will be used for the detection of

red-shifted Stokes Raman signals. Different explosives are

identified on the basis of Raman shifts which are unique for

particular compound. The system will have inbuilt software

for automatic analysis of the spectra and identification of

the threats by comparing with the stored spectral database

of the explosives.

Crowd Control Dazzler

It is propose to mount scanning laser dazzling system on a

military vehicle for a wide-scale crowd control. The system

would be engineered to fit on the vehicle and attended to by

a crew of at least two personnel--one to aim and operate the

weapon, and the other to monitor its systems via laptop.

Air Defence Long Range Dazzler

Exposure to a strong laser light source results in flash

blindness and afterimages. In flash blindness, exposure to a

very bright light source deprives pilot of vision for a period

of time ranging from a few seconds to a few minutes. Also

the laser illumination filled the flight deck with a bright

light, thus makes it difficult to concentrate on the flight

instruments as well and adversely affects pilots intended

actions. The development of long range dazzling system

finds application against rogue airplanes venturing in no fly

zone for protection of critical infrastructures.

Vehicle Mounted Ordnance Disposal of

Explosives

The System is specifically developed for neutralisation of

explosive devices from safe stand-off distances by focusing

laser energy on the munitions casing thereby heating it until

the explosive filler ignites and start.

Anti-Missile Defense System

In an antimissile defense system, laser is used to dispose the energy of warhead, not by

vaporizing or melting it, but by partially damaging the missile, say by drilling a hole.

Tremendous energy is required to completely burn the missile, which is not practicable.

If a guided vane of a missile is fractured, several vibrations will be developed in the

airframe thereby disintegrating major sensitive portion of the missile. Two types of anti-

missile defense systems have been visualized. One such system, laser kill system is

completely earthbound here; early warning microwave radar gives a rough position of the

approaching missile. Then a lidar aligned to the target by the tracking radar gives the

precise position of the missile. This data is fed on to another high intensity laser beam

which actually does the killing. To exploit the laser's killing capability, a high speed

servo system and a complex focusing system are essential. A schematic diagram is shown

in figure 6

Figure 6

The other anti-missile defense system is the orbiting space station, equipped with

detecting, tracking and killing laser devices. An infrared homing system on the laser

weapon is used to close on an enemy vehicle and then fire a high energy laser beam.

Firing by laser weapons would not change the positional or altitude stability of the space

station. It is predicted that the lasers would ultimately make inter-continental ballistic

missiles (ICBM's) obsolete.

Laser Proximity Fuze

The proximity fuze, developed in the US using a solid-state laser, detonates the missile

warhead when it comes within the range of its target. The higher maneuverability of the

missile is expected to improve its performance a great deal in close in aerial combat. It is

also claimed that the proximity fuze and the warhead will enable the missile to destroy its

target without hitting it directly. The image shown in figure 7 depicts a solid-state vehicle

mounted laser that could defeat incoming missiles and artillery fire. Directed energy

weapons are also at the forefront of precision strike.

Figure 7

Laser Guns

For decades, the Army has tried -- and essentially failed -- to develop alternative

weapons that target threats before they can reach ground troops. One earlier

technology was called the Trophy Active Protection System, which in concept

would have fired a shotgun-like blast of pellets at incoming rocket-propelled

grenades and antitank missiles. Dissipating the heat laser beams generate is one

problem the military has faced in its efforts to weaponise lasers, which new,

proprietary technology is overcoming. The technology consists of a laser, a power

source and a command and control element. Development of an effective power

source -- something that could generate enough energy to destroy incoming

projectiles -- has been another key advancement. At the most fundamental level,

laser weapons are based on the concept of delivering a large amount of stored

energy from the weapon to the target, thus producing structural and incendiary

damage effects. A directed energy weapon delivers its effect at the speed of light,

rather than supersonic or subsonic speeds typical of projectile weapons. The lasers

basically obliterate their targets.

One of its kind laser gun developed by an American company in 1962

The laser rifle….that was developed by an American company and presented for the first time in

1962 was one of its kind that was lighter than the infantry rifle used by soldiers. 10 Kg baggage

in form of batteries make impossible to shoot 10,000 times. The in the target is quite small. Only

if the enemy coincidentally looks into the muzzle of the laser rifle he’ll have serious eye damage

even at a distance of 1.5km as a result of strong dazzling.

CHAPTER 4

Status of Laser Development in India

India's Defence Research and Development Organization (DRDO) have developed a laser-based

weapon that will impair vision temporarily to control unruly crowds such as Kashmir’s stone-

throwing mobs. The non-lethal military gadget would be supplied to para-military forces in

Jammu and Kashmir within three months, a senior DRDO official said. When turned on, the

gadget, called laser dazzler, sends out radiation to immobilize individuals or crowds without

causing permanent injury. The green rays can throw a wave of agony nearly 250 meters away.

A.K .Maini, who heads the DRDO’s Laser Science and Technology Centre, told HT hand-held

laser dazzlers with a range of 50 meters would be supplied to paramilitary forces by October for

feedback on performance.

Figure 8. Anti-missile system that locates, tracks, intercepts, and destroys incoming missiles using high energy laser beam from land.

A vehicle-mounted weapon system for engaging mobs at nearly 250 meters would be ready by

the end of next year. What makes the laser effective is that it doesn’t have to be aimed and shot,

it moves like a large circle with a spread of almost 20 meters. It will allow security forces to

disperse crowds without inflicting life-threatening injury. Maini said the system was different

from Western gadgets that employed millimeter wave technology to repel crowds by targeting

different parts of the body. He explained, “It’s not a stun gun. The laser dazzler targets only the

eyes. It could be the perfect solution to de-escalate aggression such as the kind caused by

Kashmir’s stone-throwing mobs.” The DRDO is also working on a laser-based ordnance disposal

system to detonate explosives from a safe standoff distance. Also in the pipeline are vehicle and

airborne laser systems to engage hostile targets such as aircraft and missiles. These technologies

may take up to two years to mature. (From Hindustan Times)India's DRDO is trying to develop

its own set of Star Wars-like weapons. From laser dazzlers to control rioting crowds to high-

powered lasers to destroy incoming missiles, DRDO is working on a slew of directed energy

weapons (DEWs). "Lasers are weapons of the future. We can, for instance, use laser beams to

shoot down an enemy missile in its boost or terminal phase,'' said DRDO's Laser Science &

Technology Centre (LASTEC) director Anil Kumar Maini, talking to TOI. According to some

military experts, the overall level of India's laser weapons is still at the early stage. The laser-

based weapon "laser dazzler" emerged in the 1980s, which were used to spot snipers and impair

their vision. China also displayed its T-99 tanks with a laser-based system in its 50th anniversary

military parade in 1999, which is said to be capable of impairing tank aimers' vision over one

thousand meters away and causing possible damage to tanks' aiming system.Indian scientists are

on the path to develop an airborne missile- intercept system that employs high-powered lasers to

destroy missiles during their boost phase. The Laser Science & Technology Center (Lastec) at

India’s secretive Defense Research and Development Organization (DRDO) has been building

up technologies that can intercept missiles early in their flight. The weapons will also be utilized

for crucial exercises by the country’s armed forces that will involve space security, cyber

security and hypersonic technology. These futuristic technologies will be incorporated in the

Ballistic Missile Defense system being pursued by India. Last year, DRDO developed an ultra-

compact, hand-held laser sensor capable of giving warning in the form of an audio beep as well

as a visual indication to the user of any impending laser threat. The device can be used by

infantry soldiers in the battlefield and also can be configured as a helmet-mounted system in a

modified package. Recently, India also tested a laser ballistic missile defense system. The laser

weapon is capable of producing 25-kw pulses that can destroy a ballistic missile at a

range of 7 km. One of these weapons is the air defense dazzler, which can engage

enemy aircraft and helicopters at a range of 10 km.

The US and DRDO collaboration

Last year the U.S. conducted a series of tests of high-powered laser weapons on a modified

Boeing 747, the ALTB (Airborne Laser Test-Bed), which directs chemical laser energy to

destroy ballistic missiles in the boost phase. “While these laser-based technologies will take time

to develop and be deployed, the DRDO along with Lastec hasmapped out the future course of

action in these areas,” a DRDO official says.

Need to Develop Laser Technology in India

There are large gaps in the development of laser technology and its production between our

country and other developed countries. Efforts in this area have been so limited in our country

that they are not even equal to the efforts made at one major institution in the USA. Not a single

reliable laser system is commercially available in the country. Though some institutions in our

country have fabricated some experimental lasers on a laboratory scale, reliable operation of

these lasers has still been a problem. As an outcome of status report of SAC to PM, a National

laser Programme has been started recently. Advantages of lasers for various applications in our

country are well known and laser research has been recognized as one of the frontier areas to be

developed in the 8th Five Year Plan. It is high time for our country to intensify the R&D efforts

in the identified areas with time bound pro- Grammies and start the production of lasers for mass

applications.

Bibliography

References from the internet

1. http://www.questia.com/library/book/laser-weapons-the-dawn-of-a-new-military-age-by-major-

general-bengt-anderberg-dr-myron-l-wolbarsht.jsp

2. http://www.fas.org/man/dod-101/navy/docs/laser/fundamentals.htm

3. http://nextbigfuture.com/2011/04/summary-of-lasers-for-weapons.html

4. http://www.ausairpower.net/APA-DEW-HEL-Analysis.html

5. http://www.economist.com/node/12502799

6. http://en.wikipedia.org/wiki/Space_warfare#Electronic_warfare

7. http://en.wikipedia.org/wiki/Dazzler_(weapon)

8.http://www.nationaldefensemagazine.org/archive/2011/November/Pages/

10TechnologiestheUSMilitaryWillNeedFortheNextWar.aspx

9. http://www.as.northropgrumman.com/products/maritime_laser/index.html

10. http://www.zdnet.com/blog/emergingtech/laser-warfare-takes-to-the-high-seas/2171

11. http://cautionindia.blogspot.in/2011/07/drdo-develops-new-laser-wepons-for.html

12. http://articles.timesofindia.indiatimes.com/2010-08-03/india/28294609_1_ballistic-missile-defence-

system-laser-beams-laser-science

13. http://www.ausairpower.net/SP/DT-Laser-ADW-2008.pdf

14)http://www.indianexpress.com/news/work-on-to-develop-laser-weapon-system-15)drdo/880404/

http://post.jagran.com/DRDO-scientists-to-develop-laser-weapon-system-1322197451

16) http://www.hexxcom.com/drdo-develops-new-laser-weapons/

17) http://the913project.wordpress.com/2010/04/30/laser-warfare-china/

18 ) http://www.spacewar.com/reports/Laser_weapon_downs_6_planes_in_Boeing_test_999.html/

19)http://ehis.ebscohost.com/ehost/detail?sid=8517db24-4488-4228-812d-

aecb82727d41%40sessionmgr104&vid=1&hid=103&bdata=JnNpdGU9ZWhvc3QtbGl2Z

DRDO websites

1. http://drdo.gov.in/drdo/labs/LASTEC/English/index.jsp?pg=whatsnew.jsp

2. http://drdo.gov.in/drdo/data/Laser%20and%20its%20Applications.pdf

Other important websites

1.Pakistan Defense org.)http://www.defence.pk/forums/indian-defence/106065-india-looks-laser-

weapons-air-missile-defense.html

2. The fire man blog) http://www.defence.pk/forums/indian-defence/106065-india-looks-laser-

weapons-air-missile-defense.html

News papers (Articles quoted from)

1. Fox news .net

2. Times Of India

3. Hindustan Times

Books

1. Bengt Anderberg, Myron Wolbarsht, “Laser weapons: The dawn of a new military age”

2. Glen P. Perram, “An Introduction to Laser Weapon Systems”

3. Philip E. Nielsen, ”Effects of Directed Energy Weapons”