Lasers, types

Laser type Lasing wavelength >. Efficiency r (%) Mode of operation Typical output power... 

Organic Dye Lasers. Organic dye lasers represent the only weU-developed laser type in which the active medium is a Hquid (39,40). The laser materials are dyestuffs, of which a common example is rhodamine 6G [989-38-8]. The dye is dissolved in very low concentration in a solvent such as methyl alcohol [67-56-17, CH OH. Only small amounts of dye are needed to produce a considerable effect on the optical properties of the solution. 

Method Laser type Range Typical apphcation... 

It is worth comparing the relative performance of a spectrometer-laser system using various laser types. The data are summarized in Table V 26). The data, though typical, depend considerably on the characteristics of the individual components of the spectrometer. 

A mode-locked Tksapphire laser, which can produce sub-ps pulses and is usually pumped by CW argon or Nd-YAG lasers. The shortest pulses coming from this laser type are exceptionally short, of the order of a few femtoseconds. 

The intriguing properties of devices made by the combination of a film-forming dye and an optical microstructure turn up in the discovery of strong coupling between excited states and photon modes in microcavities, creating Rabi-splitted polariton modes [211]. They occur in materials with narrow absorption bands (e.g., porphyrins and cyanine dyes) and may pave the way to new laser types and fundamental insights into the interaction of matter and light. 

The possibility of tuning the frequency of a laser line inside a frequency range by several methods, depending on the laser type. 

Table 1 gives wavelengths and output powers for some important laser types operated in a continuous-wave (cw) or pulsed mode. The pulsed lasers normally have much higher peak powers but there are technical or theoretical limitations of the maximum repetition frequency, which means that their time-averaged intensity is often below that of the cw lasers. 

Characteristic Features of Lasers as Spectroscopic Light Sources r Table 1. Output power of some importarit laser types... 

Because several laser types are able to generate extremely short and powerful light pulses, they are especially useful for this method. 

In this reciew the attempt is made to exhibit some of the possibilities of laser applications in modem spectroscopy. The rapid development of new laser types and the improvement of the existing models lend lasers steadily increasing importance as spectroscopic light sources, and it seems that the laser revolution is only just beginning. These laser developments lead in different directions ... 

A detailed description of the different laser types and an extensive list of references is, for instance, given in ... 

Boulon G (1987) In DiBartolo B (ed) Spectroscopy of solid-state laser-type materials. Plenum Press, NY, pp. 223-266 Boulon G (1997) In DiBartolo B (ed) Spectroscopy and dynamics of Collective Excitations in Solids. Plenum Press, NY Brenier A, Suchocki A, Pedrini C, Boulon G, Made C (1992) Phys Rev B 46 3219-3227... 

Laser Type Common Wavelengths ( xm) Maximum Output Power (W)" Applications... 

The most recent development is the video extensometer which claims to overcome all of the disadvantages of the contact, optical and laser types. A... 

Wavelength characteristics of available laser types are given in Table I. 

Published by K.K, Mittai for Pragati Prakashan, Laser Typesetting Pragati Laser Type Setters Pvt. Ltd.. (Phone 2661657 Meerut. Printed at Arihant Electric Presss, Meerut. 

The methods of wind velocity measurement include (a) Pitot, (b) vane, (c) cup, (d) propeller or turbine, (e) thermal, (f) Doppler, (g) acoustic, and (h) laser-type designs. These devices can detect velocities in nautical miles per hour units (1.85 km/h = 101 fpm) or in knots up to 600 knots (60,000 fpm) at the following elevations designs a, b, and c—tower height f—60-600 m thickness at up to 1,500 m. 

Laser pyrolyzers are practically the only type of radiative heating pyrolyzer with certain applicability. Attempts were made in the past to use a strong light/heat source and focus the beam with lenses [20] to achieve the desired power output. However, the laser as a radiative energy source is much more convenient. The laser beam can be focused onto a small spot of a sample to deliver the radiative energy. This provides a special way to pyrolyze only a small portion of a sample. A variety of laser types were used for pyrolysis purposes normal pulsed, Q-switched, or continuous wave (cw) [21], at different energy levels. More common are the normal pulsed high-power lasers. 

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