Laser diode

A laser diode, also called a diode laser or semiconductor laser, is a semiconductor device like a light-emitting diode in which a diode pumped directly with electric current creates lasing conditions at its junction. Electrons recombine with holes in the intrinsic region of a PIN diode structure, and all modern devices use a double-heterostructure design that confines carriers and photons to make recombination and light generation more likely. The semiconductor material sets the wavelength, from infrared to ultraviolet. Laser diodes are the most common type of laser, used in fibre-optic communications, barcode readers, laser pointers, disc players and recorders, and laser printing. The first to run continuously at room temperature was a double heterostructure shown in 1970 almost simultaneously by Zhores Alferov and collaborators in the Soviet Union and by Morton Panish and Izuo Hayashi in the United States.