diodilaser

A diodilaser, more commonly called a diode laser, is a laser that uses a semiconductor diode as its gain medium. The active region is a p-n junction within a semiconductor material, typically gallium arsenide (GaAs) or indium phosphide (InP), arranged in an optical cavity. When forward biased, carriers injected across the junction produce stimulated emission, and optical feedback from the cavity yields coherent laser light.

Diode lasers are built in a variety of forms. They may be edge-emitting diodes with a cleaved facet cavity, or vertical-cavity surface-emitting lasers (VCSELs) that emit perpendicularly to the chip surface. External cavity diode lasers (ECDLs) use a diffraction grating to select a narrow wavelength, while integrated structures rely on distributed feedback or other cavity designs. The choice of semiconductor materials determines the emission wavelength, spanning from the visible region (around 405–700 nm) to the near and mid-infrared (roughly 750–2000 nm and beyond with certain materials).

Key characteristics include compact size, high electrical-to-optical efficiency, and the potential for high reliability. Diode lasers can operate in continuous or pulsed modes, with output powers ranging from milliwatts in single-mode devices to several watts in high-power arrays. They are widely used as pump sources for other lasers, as light sources in fiber-optic communications, in data storage read heads, printers, barcode scanners, and various sensing and medical systems. Safety considerations include laser class ratings and appropriate eye and skin protection.

The diode laser was developed in the 1960s and became commercially important in the following decades, evolving through material advances and improved fabrication to its diverse present applications.