What Are Laser Applications?

Laser applications are the practical uses of coherent, monochromatic, and highly collimated light produced by stimulated emission, spanning industrial manufacturing, precision measurement, information storage, medical treatment, and scientific instrumentation. Because lasers concentrate optical power to exceptionally high irradiance levels while maintaining spectral purity and spatial coherence, they enable operations that are either impractical or impossible with conventional light sources. The breadth of application domains reflects the wide range of laser types available, from continuous-wave semiconductor diode lasers operating at milliwatt power levels to pulsed solid-state and gas lasers delivering megawatts in nanosecond bursts.

Laser technology traces its origins to the theoretical framework of stimulated emission developed by Albert Einstein in 1917 and the first working laser demonstrated by Theodore Maiman at Hughes Research Laboratories in 1960. Subsequent decades saw laser types proliferate and costs fall, driving adoption across commercial and industrial sectors.

Manufacturing and Material Processing

Industrial material processing represents one of the largest application domains for lasers. Laser cutting, welding, drilling, and surface hardening are performed with CO2 lasers at wavelengths around 10.6 micrometers and fiber lasers operating near 1 micrometer, selected based on the material's optical absorption characteristics. Stereolithography, one of the foundational additive manufacturing techniques, uses an ultraviolet laser to photopolymerize liquid resin layer by layer, as described in the NIST additive manufacturing program, which tracks laser-based fabrication methods as a core area of advanced manufacturing metrology. Laser marking and engraving are widely used in electronics, automotive, and medical device manufacturing for permanent, high-contrast part identification that withstands harsh environments.

Sensing and Measurement

Precision measurement is a domain where laser coherence and directionality provide advantages unmatched by other technologies. Laser interferometers measure displacements to sub-nanometer precision in semiconductor lithography, coordinate measurement machines, and gravitational wave detectors such as LIGO. Laser gyroscopes, based on the Sagnac effect in a closed optical path, serve as inertial navigation references in aircraft, missiles, and spacecraft where mechanical gyroscopes would be too slow or fragile. Photoacoustic techniques use pulsed laser excitation to generate ultrasonic waves in absorbing materials, enabling nondestructive evaluation and subsurface imaging of biological tissues and industrial components. The NIST measurement science programs maintain laser radiometry standards used to calibrate optical power meters and irradiance references throughout industry. Laser range-finding and lidar extend these measurement principles to three-dimensional mapping of terrain, buildings, and autonomous vehicle surroundings.

Information Storage and Optical Recording

Optical recording uses focused laser beams to read and write data on reflective disc substrates. In compact disc (CD) systems, a 780 nm semiconductor diode laser reads the series of pits and lands on a polycarbonate disc, with the pit transitions encoding binary data through changes in reflected intensity. DVD and Blu-ray formats progressively shortened the laser wavelength to 650 nm and 405 nm, respectively, to reduce the minimum pit size and increase storage density. The IEC 60908 standard and its successors define the optical and electrical parameters that disc and drive manufacturers must meet for interoperability. Although solid-state storage has largely displaced optical discs for consumer data storage, optical recording remains in use for archival, broadcast media, and software distribution applications requiring long-term physical media stability.

Applications

Laser applications extend across a range of fields, including:

• Ophthalmic surgery including LASIK corneal correction and retinal photocoagulation
• Fiber-optic telecommunications where semiconductor lasers serve as modulated optical transmitters
• Scientific spectroscopy, including Raman and fluorescence analysis of molecular structure
• Defense systems including laser rangefinders, target designators, and directed-energy applications
• Barcode scanning and point-of-sale systems in retail and logistics
• Laser-based printing and photocopying using scanning laser beams to form electrostatic images