What is a Semiconductor Laser?
Semiconductor lasers are laser devices that make use of semiconductors in order to product a tight beam. Sometimes referred to as a laser diode, the semiconductor laser is utilized in a number of different applications today. While originally developed for use with high tech research equipment and explored as a military tool, these lasers have found their way into such industries as telecommunications, education, and the retail industry. Within the telecommunications industry, the semiconductor functions as part of the process of carrying signals along optic fibers. The photon stream of the laser helps with the efficient conduction of many signals at one time, helping the process of audio communications to be more efficient even as a larger load can be carried over greater distances. This application of the semiconductor laser has also enhanced the ability to provide wireless connections with greater stability and efficiency. Within the education field, a semiconductor laser is useful
The basic ingredients for a laser are the same, no matter whether the laser is the size of a whole building or the size of a grain of sand. A laser cavity consists of a gain medium (gas, liquid or solid) that amplifies light; and feedback structures that reflect the light back through the gain medium. Semiconductor lasers, or laser diodes,work on the same principle as for bigger lasers. They function as an optical oscillator by stimulating a chain reaction of photon emission inside a tiny cavity. They are made in clean-rooms on crystalline semiconductor wafers by depositing thin films of materials to form different layers. The most common semiconductors used in laser diodes are compounds based on gallium arsenide (with emission wavelengths of 750 to 900 nm in the infrared), indium gallium arsenide phosphide (1200 to 1700 nm in the infrared) and gallium nitride (near 460 nm in the blue or 405 nm in the violet). In the semiconductor diode laser electrical charge carriers, that is negativ
Chances are you’ve used a semiconductor laser in the last few days without even knowing it. If you’ve watched a DVD you’ve “looked through” one; if you’ve been into a grocery store and had a product swiped through the checkout you’ve bought with one; if you’ve made a long-distance telephone call by fiber-optic cable you’ve “talked through” one; and if you’ve printed something with a laser printer your printout has passed very near one. Semiconductor lasers make powerful, precise beams of light (like ordinary lasers), but they’re about the same size as simple LEDs—the little colored lamps you see on electronic instrument panels. Photo: The smaller circle on the bottom left of this photo is a semiconductor laser diode in a CD player. The larger, blue-tinted circle on the top right is a lens that reads the reflected light bouncing down off the CD. Never attempt to look at the laser light in a CD player: you can easily blind yourself. If you’ve read our article on diodes, you’ll already ha
