Yttrium-aluminum garnet laser

Neodymium-doped yttrium aluminum garnet laser (NldiYAG)... 

Before the invention of lasers in 1960 (Maiman), radiation emitted by the mercury arc, especially at 435.8 and 404.7 nm, has been u.sed for exciting Raman spectra (Brandmiiller and Moser, 1962). Today, most types of lasers ( continuous wave (cw) and pulsed, gas, solid state, semiconductor, etc.), with emission lines from the UV to the NIR region, are used as radiation sources for the excitation of Raman spectra. Especially argon ion lasers with lines at 488 and 515 nm are presently employed. NIR Raman spectra are excited mainly with a neodymium doped yttrium-aluminum garnet laser (Nd YAG), emitting at 1064 nm. 

The technique of laser heating in a DAC is based on three main features optical transparency of diamond anvils the samples can be heated via the optical absorption of intense laser radiation, and the temperature can be determined from the thermal radiation spectrum of the heated sample using the Planck formula [10]. Laser radiation for heating of a sample in a DAC was first implemented by Ming and Bassett [11], who used a pulsed ruby laser, and a continuous-wave Nd-YAG (yttrium-aluminum-garnet) laser to heat samples in a DAC above 3300 K, and up to 2300 K, respectively. Today two types of continuous wave infrared (IR) lasers are extensively used in laser heating experiments Solid state lasers (Nd-doped YAG, or YLF (yttrium-lithium-fluorite) crystals with the most intense line at... 

Several of the early problems associated with Raman have been overcome. Fluorescence emission from the sample was a problem when visible light sources were used. Now, NIR sources such as the NdrYAG (neodymium yttrium aluminum garnet) laser diminish fluorescence and provide variable power levels for measurement optimization. The major difficulty with Raman is the lack of experienced interpretive spectroscopists and detailed texts. Even NIR seems commonplace when compared with the number of Raman applications. Only time will solve these latter problems as more applications occur and more are published. 

The thicknesses of monolayers and polymer brushes on the silicon substrates were evaluated as the height difference between the monolayer surface and bared Si-wafer surface by atomic force microscopy (AFM). The thickness of the OTMS monolayer was estimated to be ca. 2.0 nm. An ellipsometer (Imaging Ellipsometer, MORITEX Co., Tokyo) equipped with a YAG (yttrium aluminum garnet) laser (532.8 nm) was also used to determine the thickness of the polymer brushes. 

Neodymium-doped yttrium aluminum garnet lasers have found extensive applications as range finders and have also become standard laboratory equipment for research in photochemistry and related fields. 

For the SHG measurements we used the frequency-doubled output of a Q-switched neodymium-doped yttrium aluminum garnet laser at 532 nm with a 7-nsec pulse width as the pump beam. 

Matthewson K, Coleridge-Smith P, O Sullivan JP, et al (1987) Biological effects of intrahepatic neodymium yttrium-aluminum-garnet laser photocoagulation in rats. Gastroenterology 93 550-557... 

A similar procedure was made recently by Honma et al. [237]. The authors used glasses in the system BaO —Ti02—Ge02-Si02, which are suitable for fresnoite-type crystallisation. The applied heat source was a cw-YAG (yttrium-aluminum-garnet) laser. 

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