A laser diode (LD), an injection laser diode (ILD) or a laser diode is a semiconductor device similar to a light emitting diode which is created at the junction of the laser diode.  laser diodes are the most common types of laser products, with a wide range of uses, including fiber optic communication, barcode readers, laser pointers, CD / DVD / Blu- reading / recording ray, laser printing, laser lighting and light beam.
A laser diode is an electric LED diode. The active region of the laser diode is intrinsic region and vectors (electrons and holes) are pumped into the region by N and P. While the LED laser diode search is initially simple PN, all modern lasers use double-actuation -eterostructure, where vectors and photons they are limited to maximize their chances of recombination and light generation.
Unlike an ordinary diode, the goal for a laser diode is to recombine all carriers in the I region and produce light. Therefore, laser diodes are produced using direct band semiconductors. Laser epitaxial diode structure is grown using one of the crystal growth techniques, usually from a N-doped substrate and augmenting the active doped layer, followed by a dopant-plug contact plating layer.
The thicker active layer consists of quantum wells, which offer a lower threshold and greater efficiency.
The laser diodes form a subset of the broader classification of the p-n junction diodes of semiconductors. The transmission power before the laser diode causes two carrier species – holes and electrons – to be “injected” on opposite sides of the p-n junction emptying region.
The holes are injected by the cap P and electrons in the doped semiconductor n. (An emptying region, without charge carriers, is formed as a result of the electrical potential difference between type n and p semiconductors, regardless of where it is in physical contact). Due to the use of the majority of the diode injection charge, this class of lasers is sometimes referred to as “laser injection” or “laser diode injection” (ILD). Since diode lasers are semiconductor devices, they can also be classified as semiconductor lasers. Or the design distinguishes diode lasers from solid-state lasers.
Another method for powering diode lasers is the use of optical pumps. The optical semiconductor lamp pump using a III-V semiconductor chip as a means of gain, and another laser (often another laser diode) as the source of the pump. OPSL offers numerous advantages over ILD, in particular with regard to wavelength selection and interference of internal electrode structures.
When an electron and a hole are present in the same region, they can recombine or “annihilate” produce a spontaneous emission – that is, the electron can re-occupy the energy state of the hole, emits a photon with an energy equal to the difference between the state original the electron and the hole. (In a conventional semiconductor junction diode, the energy released by the recombination of electrons and holes is removed as phonons, i.e., the vibration of the reservoir, rather than photons).
Spontaneous emission under leaching produces similar properties to LEDs. Spontaneous emission is necessary to initiate laser oscillations, but it is one of many sources of inefficiency once the laser oscillates.
The difference between semiconductor laser photon and semiconductor junction emitting diode semiconductor (not emitting light) is the type of semiconductor used, the physical structure that gives the possibility of emission of the atom and photons. These photon-emitting semiconductors are the so-called “direct bandgap” semiconductors. The properties of silicon and germanium, which are a single semiconductor element, the bandgap do not align properly to allow the emission of photons, and are not considered “direct”.
Other materials, so-called semiconductor compounds crystalline structures identical to those of silicon or germanium, but the use of alternative arrangements of two different atomic species to chess-like type to break the symmetry. The transition between the materials in the alternative model creates the critical property “direct bandgap”.
Gallium phosphide arsenide, gallium antimonide and gallium nitride are all examples of compound semiconductor materials that can be used to create light-emitting diodes.