Laser technologies wavelengths

Unlike these light sources, laser technology relies on a concept known as stimulated emission. Wlien an excited atom is stimulated by a photon, light is emitted at precisely the same wavelength and precisely in ph ase with the light wave that stimulated it. 

This paper explores the trade-offs of gem damage during LIBS analysis and data quality under a variety of analytical conditions. Two lasers, a Big Sky Laser Technology (now Quantel USA) Nd-YAG nano-second laser operated at its fundamental wavelength of 1064 nm, and a Raydiance, Inc., pico-second laser operated at its fundamental wavelength of 1552 nm as well as harmonics at 776, 517.2, and 388 nm, are used in separate LIBS systems. Furthermore, the use of inert gas environment (He or Ar) is explored to increase peak intensities at lower laser power and sample damage. 

Continuous-wave laser technology directs a continuous laser beam at the target, and the distance is calculated on the basis of frequency, wavelength, and phase shift in the returning beam. It is used for short-range, extremely high-accuracy, clean-air applications usually for positioning and only infrequently for level. 

One interesting piece of equipment developed to measure oxygen content of the blood is produced by the Centre for Biomedical Technology in Australia [41]. It consists of five 1W lasers at wavelengths of 780, 800, 830, 850, and 980 nm and uses a photodiode receiver. It uses the hemoglobin/deoxy-hemoglobin absorbance differences mentioned earlier and throws in the S02 content of the blood for good measure. 

Previously, a multiple, fixed-wavelength sensor for measuring the gas temperature of detonation products was reported [1]. While this sensor provided important results, the rapid, broad-wavelength-scanning capabilities of advanced diode-laser technologies allow for a simpler and more robust technique to measure both temperature and pressure simultaneously [4, 5]. This technique, described below, provides gas temperature and pressure histories, spanning 2000-4000 K and 0.5-30 atm, respectively, with microsecond time response. 

It is the first step in the whole field of photochemistry, that generates radicals and initiates subsequent reactions, and this is why photodissociation has been studied actively first in this field. However, the primary interest in photochemistry has been the question which radicals can be formed from which parent molecules at which wavelength and what subsequent reactions occur. Detailed studies about the dynamics of photodissociation have been performed only more recently, mainly because they became only possible with modern laser technology. Today, most experimental work is devoted to a detailed characterisation of process (1) itself, with the intention to understand zhe motion of both nuclei and electrons during fragmentation. 

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