LASERS

LASERS. Laser is an acronym for light amplification by stimulated emission of radiation. External energy pumped into the atoms of the lasing medium excites electrons to higher energy states; returning to their base state, they emit photons. Cascading photons produce a narrow, tightly focused beam of intense, coherent, monochromatic light.

The special properties of laser beams—intensity, coherence, directionality—held obvious promise for military purposes. Beginning promptly with the 1961 invention, mission‐oriented laser research and development centered on such practical applications as range finding and guidance.

Operational range finders began seeing field service during the Vietnam War by the mid‐1960s. Incorporated in fire control systems, they especially suited direct fire weapons like tank guns; such units for the M‐60 tank began service in 1968. Immediately successful, laser range‐finding and fire control systems rapidly became standard equipment. Laser simulators have also sharply enhanced training realism for tank gunners and infantry small arms.

Laser guidance, teaming ground‐based or airborne target designators with projectile‐borne sensors, was one of the precision methods that began revolutionizing air attack on surface targets from the late 1960s onward. The designator directs a laser beam at the target, the laser seeker picks up the reflected light, and the bomb or missile homes in on the illuminated target.

Laser‐guided bombs made their first appearance under the U.S. Air Force's Paveway program. Field modification kits for several standard bomb models began reaching Vietnam in 1971. Each included a laser seeker, guidance unit, and control canards bolted to the bomb's nose, enlarged tail fins bolted to the rear. This first Paveway generation met outstanding success in 1972 attacks on North Vietnamese bridges. Paveway II arrived in 1980, Paveway III in 1987, each kit more sophisticated and costly than its predecessor.

Augmented with an off‐the‐shelf rocket motor, Paveway II also became the basis for the navy's Skipper II air‐to‐surface missile. It entered service in 1985 as a low‐cost (though less capable) alternative to the Maverick, a 1977 version of which was the first U.S. laser‐guided missile. Superseded in 1983 by an upgraded model with a better laser seeker and larger warhead, the Maverick now largely serves a Marine close air support role.

The army fielded its first laser‐guided missile, the Hellfire, in the early 1980s. Developed specifically as an antitank missile for Apache attack helicopters, it could acquire its target after launch. Outstanding capabilities and performance led the army to adapt Hellfire for other aircraft and make it the focus of antitank tactics.

Less successful was the Copperhead cannon‐launched guided projectile, also intended as a tank killer. Production began in 1981, but persistent technical difficulties and escalating costs ended its procurement in 1990.

From the beginning, the laser's potential as a weapon excited military interest, peaking in the proposed missile defense system called the Strategic Defense Initiative. Other potential military roles for lasers, more or less speculative in the early 1990s, include laser equivalents of radar (LADAR), beam‐riding missiles, and communication systems.
[See also Antitank Weapons; Missiles.]

Bibliography

Bengt Anderberg and and Myron L. Wolbarsht , Laser Weapons: The Dawn of a New Military Age, 1992.
Guy Hartcup , The Silent Revolution: Development of Conventional Weapons, 1945–85, 1993.

Barton C. Hacker