Smart Electronics New KY-008 3pin 650nm Red Laser Transmitter Dot Diode Copper Head Module for Arduino AVR PIC DIY (B.2)
A laser diode module provides all the necessary to create an emitting laser frequency. Laser diodes have much in common with regular diodes that do not emit visible light. They are formed from a semiconducting material and are created by joining a p-type and an n-type material together. All diodes, including laser emitters, then have an intrinsic region that forms with no loose holes or electrons. This is called the depletion zone. It is here that the magic happens in a laser diode.
These diodes are formed by using semiconductor compounds, which means a combination of two or more atomic types. This creates a unique band gap that facilitates the emission of photons, or light. When a charge is injected into the diodes, there is a constant stream of electrons and holes combining in the intrinsic region. This combination creates an atomic condition that allows for the release of a photon.
By modifying the materials used in the laser diode, the energy released during this combination can be controlled and the color of light can be selected. This is very similar to the functionality of the modern LED. Regular diodes do not have the necessary atomic structure to release photons, and usually just produce lattice vibrations .