Diagram of the structure of a laser diode

The structure diagram of the laser diode is shown in figure (a).
The physical structure of the laser diode is to place a layer of optically active semiconductor between the junction of the light-emitting diode, and its end surface has a partial reflection function after being polished, thus forming an optical resonant cavity. In the case of forward bias, the LED junction emits light and interacts with the optical resonant cavity to further stimulate the emission of single-wavelength light from the junction. The physical properties of this light are related to the material.
The working principle of a semiconductor laser diode is theoretically the same as that of a gas laser. Figure (b) is the representative symbol of the laser diode. Laser diodes have been widely used in low-power optoelectronic devices such as optical disc drives on computers and print heads in laser printers.