High-power laser diode structure
The active region of the laser diode is in the intrinsic (I) region, and the carriers (electrons and holes) are pumped into that region from the N and P regions respectively. The basic device structure consists of a rectangular parallelepiped of a direct bandgap semiconductor, usually a III–V compound semiconductor such as GaAs, incorporat-ing a forward-biased, heavily doped p–n junction to provide the optical gain medium in a resonant optical cavity . 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. High power diode lasers, operating in long pulse width mode, require high reliability and extended lifetime in the medical aesthetic application.
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