Photonics—Light in the Twenty-First Century

Abstract

When first invented, the laser was described as an invention in search of an application. Few predicted that lasers would ultimately have applications in medicine, agriculture, commerce, optical communication, astronomy, manufacturing, and security. With light now having uses in almost every area of human endeavor, it’s no wonder that it is said that we have entered the photonic age, a time in which photons are used in a manner similar to the way electrons are employed in electronics.

Glossary of Terms

acousto-optic modulator

Acoustic (sound) waves diffract light waves to produce a modulated signal.

adaptive optics

A technology designed to improve the performance of astronomical optical systems by compensating for distortions introduced by medium between object and image.

compact disc (CD)

Optical storage device that uses a laser to write and read data stored as small pits on a reflecting surface.

compact disc read-only memory (CD-ROM)

Compact disc used for computer input.

digital versatile disc (DVD)

Optical disc capable of storing full-length movies.

diode laser

Semiconductor junction diode that produces coherent light.

hogel

A computer-generated holographic pixel.

holographic data storage

A data storage system in which information is stored throughout a volume rather than just on the surface, as is the case with other optical storage methods.

light-emitting diode (LED)

Semiconductor junction diode that emits light of a particular color when excited by an electric current.

magneto-optical (MO) disc

Stores data that can be read out using the Kerr magneto-optical effect.

magneto-optical Kerr effect

Rotation of the plane of polarization when reflected by a magnetic surface. Direction of rotation depends on direction of magnetization.

MiniDisc ( MD)

Miniature compact disc for recording digital audio.

multiwavelength astronomy

The study of the universe using a wide range of wavelengths.

optical computer

A device that uses visible or infrared light, rather electric current, to perform digital computations.

optical fiber

Glass fiber capable of transmitting data optically.

optical tweezers

Instruments that employ laser light to manipulate and trap micro particles.

photodiode

Semiconductor junction that conducts electricity when illuminated by light. Used to detect reflected signals from an optical storage disc.

photonics

A branch of physics and technology that deals with the properties and applications of photons.

spatial light modulator

A device used in holographic data storage systems to modulate amplitude, phase, or polarization of light waves in space and time.