Edge-emitting laser diodes shoot their beam out from the edge of the chip, parallel to the semiconductor layers. 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. : 3 Driven by voltage, the doped. Semiconductor laser diodes come in many shapes and sizes. Hall and, largely because they're so compact and inexpensive, are now the most widespread lasers in the world. The emitted light waves have the same wavelength, frequency, and.