This coherent light is produced by the laser diode using a process termed as “Light Amplification by Stimulated Emission of Radiation”, which is abbreviated as LASER. And since a p-n junction is used to produce laser light, this device is named as a laser diode. A laser diode (LD, also injection laser diode or ILD or semiconductor laser or diode laser) is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction. Laser diodes offer high power for their size and produce electrical-power-efficient laser radiation. When electric current flows through the p-n junction, the gain is.