Examples of lasers

A recent example of laser flash-lamp photolysis is given by Hippier etal [ ], who investigated the temperature and pressure dependence of the thennal recombmation rate constant for the reaction... 

In choosing fhe examples of lasers discussed in Sections 9.2.1 to 9.2.10 many have been left ouf. These include fhe CO, H2O, HCN, colour cenfre, and chemical lasers, all operating in fhe infrared region, and fhe green copper vapour laser. The examples fhaf we have looked af in some defail serve to show how disparate and arbifrary fhe materials seem to be. For example, fhe facf fhaf Ne atoms lase in a helium-neon laser does nof mean fhaf Ar, Kr and Xe will lase also - fhey do nof. Nor is if fhe case fhaf because CO2 lases, fhe chemically similar CS2 will lase also. 

A final example of laser measurement techniques is measurement of the velocity of fluid flow (79) (see Flow measurement). If a laser beam is directed into a transparent fluid, some of the light may be scattered with a frequency shift zy given by... 

This procedure offers the possibiUty of remote noncontact velocity measurement, where no probes disturb the flow. It is thus compatible for use with hot or corrosive gases. Commercial laser velocimeters have become weU-developed measurement tools. Examples of laser velocimetry include remote measurement of wind velocity, measurement of vortex air flow near the wing tips of large aircraft, and in vivo measurement of the velocity of blood flow. 

The third problem also concerns the choice of whether to leave out certain material. In a book of this size it is not possible to cover all branches of spectroscopy. Such decisions are difficult ones but I have chosen not to include spin resonance spectroscopy (NMR and ESR), nuclear quadrupole resonance spectroscopy (NQR), and Mossbauer spectroscopy. The exclusion of these areas, which have been well covered in other texts, has been caused, I suppose, by the inclusion, in Chapter 8, of photoelectron spectroscopy (ultraviolet and X-ray), Auger electron spectroscopy, and extended X-ray absorption fine structure, including applications to studies of solid surfaces, and, in Chapter 9, the theory and some examples of lasers and some of their uses in spectroscopy. Most of the material in these two chapters will not be found in comparable texts but is of very great importance in spectroscopy today. 

TABLE 2. Classes Types> and Representative Examples of Laser Sources... 

A famous example is the photodissociation of H2O leading to a preferentially populated A component of the OH fragment, which forms the basis of the astronomical OH maser observed in interstellar clouds [1068]. There are many more examples of laser spectroscopy of chemical reactions, some of which can be found in [1069-1073]. 

More examples of lasers in analytical chemistry can be found in [1384-1386]. 

The preceding selection of examples of laser spectroscopic applications is somewhat arbitrary and by no means complete. The progress in this field may be measured by the increasing variety of conferences and workshops on applications of laser spectroscopy in science and technology. A good survey can be found in many conference proceedings of the Society of Photo-optical Instrumentation and Engineering (SPIE) [1572]. The reasons for this rapid expansion of applications are manifold ... 

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