Search results
Results from the WOW.Com Content Network
In semiconductor laser theory, the optical gain is produced in a semiconductor material. The choice of material depends on the desired wavelength and properties such as modulation speed. It may be a bulk semiconductor, but more often a quantum heterostructure. Pumping may be electrically or optically . All these structures can be described in a ...
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. [1]: 3
The height of the lines and bars gives an indication of the maximal power/pulse energy commercially available, while the color codifies the type of laser material (see the figure description for details). Most of the data comes from Weber's book Handbook of laser wavelengths, [1] with newer data in particular for the semiconductor lasers.
The new semiconductor laser devices operated only at cryogenic temperatures (typically that of liquid nitrogen, that is, at 77K or –196 °C). For practical use, it would be necessary to demonstrate diode laser action, continuous-wave, at room temperature.
Lasers are used in fiber-optic and free-space optical communications, optical disc drives, laser printers, barcode scanners, semiconductor chip manufacturing (photolithography, etching), laser surgery and skin treatments, cutting and welding materials, military and law enforcement devices for marking targets and measuring range and speed, and ...
Diagram of a simple VCSEL structure. The vertical-cavity surface-emitting laser (VCSEL / ˈ v ɪ k s əl /) is a type of semiconductor laser diode with laser beam emission perpendicular from the top surface, contrary to conventional edge-emitting semiconductor lasers (also called in-plane lasers) which emit from surfaces formed by cleaving the individual chip out of a wafer.
This allows quantum dot lasers to be fabricated to operate at wavelengths previously not possible using semiconductor laser technology. [1] One challenge in the further advances with quantum dot lasers is the presence of multicarrier Auger processes which increases the nonradiative rate upon population inversion. [ 2 ]
If the temperature of a semiconductor Fabry–Perot laser changes, the wavelengths that are amplified by the lasing medium vary rapidly. At the same time, the longitudinal modes of the laser also vary, as the refractive index is also a function of temperature. This causes the spectrum to be unstable and highly temperature-dependent.