Light amplification by stimulated

LASER, light amplification by stimulated emission of radiation... 

The term laser is an acronym constmcted from light amplification by stimulated emission of radiation. The first operating laser was produced in 1960 (1). This laser, which used a crystal of mby [12174A9-17, chromium-doped alumina, Al202 Cr, and emitted a pulsed beam of collimated red light, immediately aroused scientific interest. 

International Union of Pure and Applied Chemistry International Union of Pure and Applied Physics Laser (Ablation) Micro Mass Spectrometry Light Amplification by Stimulated Emission of Radiation Liquid Chromatography... 

The word LASER is an acronym for Light Amplification by Stimulated Emission of Radiation. The physical process upon which lasers depend, stimulated emission, was first elucidated by Einstein in 1917 (1). Einstein showed that in quantized systems three processes involving photons must exist absorption, spontaneous emission, and stimulated emission. These may be represented as follows ... 

Lasers are devices for producing coherent light by way of stimulated emission. (Laser is an acronym for light amplification by stimulated emission of radiation.) In order to impose stimulated emission upon the system, it is necessary to bypass the equilibrium state, characterized by the Boltzmann law (Section 9.6.2), and arrange for more atoms to be in the excited-state E than there are in the ground-state E0. This state of affairs is called a population inversion and it is a necessary precursor to laser action. In addition, it must be possible to overcome the limitation upon the relative rate of spontaneous emission to stimulated emission, given above. Ways in which this can be achieved are described below, using the ruby laser and the neodymium laser as examples. 

In contrast to spontaneous emission, induced emission (also called stimulated emission) is coherent, i.e. all emitted photons have the same physical characteristics - they have the same direction, the same phase and the same polarization. These properties are characteristic of laser emission (L.A.S.E.R. = Light Amplification by Stimulated Emission of Radiation). The term induced emission comes from the fact that de-excitation is triggered by the interaction of an incident photon with an excited atom or molecule, which induces emission of photons having the same characteristics as those of the incident photon. 

Since the field of spectroscopic laser applications is so vast and the number of published papers exceedingly large, this review cannot be complete. However, the author has tried to give a reasonable survey of what has been done and to offer some ideas about what can be done in modem spectroscopy with such an interesting and stimulating invention as the laser (Light Amplification by Stimulated Emission of Radiation). 

The term LASER stands for Light Amplification by Stimulated Emission Radiation... 

Stimulated emission of photons. This process consists of electronic transitions from the excited energy level to the lower one stimulated by an external radiation of the appropriate frequency ( 2 - E fh and constitutes the basis of the laser (light amplification by stimulated emission of radiation) phenomenon. 

Laser Diode (LD)—Light Amplification by Stimulated Emission of Radiation. An electro-optic device that produces coherent light with a narrow range of wavelengths, typically centered around 780 nm, 1320 nm, or 1550 nm. Lasers with wavelengths centered around 780 nm are commonly referred to as CD Lasers. 

Laser Laser is an acronym for Light Amplification by. Stimulated Emission of Radiation. Lasers are important in flow cytometry because, as a result of their coherent output, they are a means of illuminating cells with a compact, intense light beam that will produce fluorescence signals that are as bright as possible over a short time period. 

Laser A source of ultraviolet, visible, or infrared radiation which produces light amplification by stimulated emission of radiation from which the acronym is derived. The hght emitted is coherent except for superradiance emission. 

A laser is a radiation source which produces a very high spectral radiance in a small spectral range at a fixed wavelength. A laser combines a radiation source with spectral isolation of its radiation - two important components of a spectrometer. The word laser is an acronym which stands for light amplification by stimulated emission of radiation. The essential elements of a laser are an active medium a pumping process to produce a population inversion and a suitable geometry or optical feedback elements (Moore et al., 1993). Most lasers are essentially Fabry-Perot interferometers whose cavities contain... 

A laser (acronym for light amplification by stimulated emission of radiation) amplifies light in a different region of the electromagnetic spectrum by the same method that the maser amplifies microwaves. 

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