Optically pumped semiconductor lasers (OPSL) use a III-V semiconductor chip as the gain medium, and another laser (often another diode laser) as the pump source.OverviewA laser diode (LD, also injection laser diode or ILD or semiconductor laser or diode laser) is a device similar to a in which a diode pumped directly with electrical current can create. A laser diode is electrically a. 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 respectivel.