Timeline of United States inventions (1946–91) of the United States Geological Survey. 1960 Gas laser A gas laser is a laser in which an electric current is discharged through a gas to produce light. The first gas laser, the Helium-neon, was invented by William R. Bennett, Don Herriott, and Ali Javan in 1960. The first continuous visible gas laser, operating at 632.8 nm in the red, was invented by A. D. White and J. D. Rigden in 1962. 1961 Spreadsheet (electronic) 1961 Wearable computer 1961 Frozen carbonated beverage 1961 Biofeedback 1962 Communications satellite 1962 Chimney starter 1962 Light-emitting diode A light-emitting-diode (LED) is a semiconductor diode
Light-emitting diode holes existing in the p-region. Free electrons are in the conduction band of energy levels, while holes are in the valence energy band. Thus the energy level of the holes is lower than the energy levels of the electrons. Some portion of the energy must be dissipated to recombine the electrons and the holes. This energy is emitted in the form of heat and light. The electrons dissipate energy in the form of heat for silicon and germanium diodes, but in gallium arsenide phosphide (GaAsP) and gallium phosphide (GaP) semiconductors, the electrons dissipate energy by emitting photons. If the semiconductor