ABSTRACT
A laser diode is a coherent light emitter that although similar to an LED has some significant differences from that device. As we investigate the laser diode in this chapter, we will note that there are many
different types of such devices. The most common laser diode is similar to an LED in that it is formed from a p-n junction, with crystal being doped to produce an n-type region and a p-type region, one above the other. Similar to an LED, a forward electrical bias results in holes and electrons being injected from opposite sides of the p-n junction into the depletion region. Like the LED, holes are injected from the doped p-type region, whereas electrons are injected from the doped n-type region.
