Laser (short for English: Light Amplification by stimulated Emission of Radiation) is a mechanism for a device that emits electromagnetic radiation, usually in the form of light that can not be seen nor can see with normal eye, through the process of stimulated emission. Usually a single laser beam, emits photons in a coherent beam. Lasers can also be said of the effects of quantum mechanics.
In laser technology, demonstrate a coherent light source that emits wavelengths of light are identified from the same frequency, the phase difference is constant and polarization. Furthermore, to produce a coherent light from the lasing medium is to control the purity, size, and shape. Continuous output of the laser with a constant-amplitude (known as CW or continuous wave), or rate, is by using Q-switching, lockingmode, or gain-switching.
In pulse operation, where a higher peak power can be achieved. A laser medium can also function as an optical amplifier when in-seed with a light from other sources. The amplified signal can be very similar to the input signal in terms of wavelength, phase, and polarization; This is certainly important in optical fiber telecommunications.
Common light sources, such as incandescent light bulbs, emitting photons of nearly the entire way, usually through the electromagnetic spectrum of wavelengths wide. The coherence is difficult to find the source of light or incoherens; where there is no fixed phase difference between the photons emitted by the light source. In contrast, lasers typically emit light photons in a narrow, polarized, coherent beam of monochromatic approach, consisting of a single wavelength or one color.
Several types of lasers, such as dye lasers and laser-solid objects vibronik (vibronic solid-state lasers) can produce light over a wide period of the waves; these properties make them suitable for the creation of a short pulse of light is very short, in the long femtodetik (10-15 seconds ). Many theories of quantum mechanics and thermodynamics can be used for laser action, despite the fact that many types of lasers are found by trial and error.
Laser symbol to alert / notification
Since the introduction of laser in 1960, as a solution to a problem , then the subsequent development of the laser has been used extensively, in a variety of modern applications, including in the areas of optical, electronic, optoelectronic, information technology, science, medicine, industry , and the military. In general, the laser is considered one of the most influential technological achievements in the 20th century.
Generally, the laser operates in the visible spectrum at a frequency of about 1014 Hertz 15 Hertz or hundreds of thousands of times the microwave frequency. At first the laser beam generating device is still large and troublesome department. In addition to inefficiency, he’d be able to function at very low temperatures. The resulting laser light has not shone straight. At the very bright light conditions too, emit easily follow the winding density of the atmosphere. At that time, a laser beam in a distance of 1 km, can arrive at its final destination at a lot of points with a deviation range of up to a matter of meters.
Demonstration equipment Helium-Neon Laser Kastler-Brossel Laboratory at the University Pierre and Marie Curie.
Some of them are the advantages of laser output power very high power is desirable for several application. However, lasers with low power even though (a few milliwatts) used in transmission, can still be harmful to human vision, because the laser light beam can result in the eyes of someone who has experience in momentary or permanent blindness.