Laser technology, development

Development of laser technology over the last decade or so has permitted spectroscopy to probe short-time events. Instead of having to resort to the study of reactants and products and their energetics and shuctures, one is now able to follow reactants as they travel toward products. Fast pulsed lasers provide snapshots of entire molecular processes [5] demanding similar capabilities of the theory. Thus, explicitly time-dependent methods become suitable theoretical tools. 

Although practical generation of energy by laser-assisted thermonuclear fusion remains well ia the future, the program has provided some of the most exacting requirements for laser technology and has led to advances ia laser equipment that have been adopted ia other areas. Thus the research and development associated with thermonuclear fusion work has helped to spur advances ia laser technology useful for many other appHcations. 

The study of deterministically driven reactive systems has become prominent as the development of laser technology over the past decades has led to laser pulses whose duration is comparable to the time scale of molecular motion (i.e., pico- or... 

Now, I want to talk about the laser. It s a personal history in part, but also I think a very important illustration of how new science and new technology develop. It s simply one of many examples, but one I happen to know personally, so that s the one I will talk about. 

Recent developments in laser technology and fast detection methods now allow the kinetic behaviour of the excited state species arising from absorption of radiation by polymers to be studied on time-scales down to the picosecond region ( ). An example of a time-resolved fluorescence spectrometer which can be used to study such ultrafast phenomena is illustrated in Figure 5 Q). 

Measurements of kp were performed by the rotating sector method and its variations until the late 1980s [Flory, 1953 Odian, 1991 Walling, 1957]. In the late 1980s advances in pulsed laser technology and size exclusion chromatography resulted in the development of a technique called pulsed laser polymerization-size exclusion chromatography (PLP-SEC) [Beuermann and Buback, 2002 Beuermann et al., 1997, 2000 Buback et al., 1986, 1992,... 

Technology development is supported by the U.S. Department of Energy (DOE). The technology has been evaluated in bench-scale tests and is not currently commercially available. According to DOE researchers, laser ablation has the following advantages ... 

However, systems with localized atoms represent only a first challenge. The next challenge is monitoring atomic motions in systems that vary in time. Following atomic motions during a chemical process has always been a dream of chemists. Unfortunately, these motions evolve from nanosecond to femtosecond time scales, and this problem could not have been overcome until ultrafast detection techniques were invented. Spectacular developments in laser technology, and recent progress in constmction of ultrafast X-ray sources, have proved to be decisive. Two main techniques are actually available to visualize atomic motions in condensed media. 

In the years since 1964, when the first passive Q-switching with organic dyes was accomplished, the use of organic dyes in laser technology has become increasingly important. Some of the most important developments in the laser field would not have been possible without organic dyes, and one can foresee even further possibilities for the use of dyes in laser technology which could be realized in the near future. 

Another revolutionary application of electronically excited molecular systems is in laser technology. Lasers are intense sources of monochromatic and coherent radiation. From their early development in 1960 they have found wide fields of application. They have provided powerful tools for the study of diverse phenomena ranging from moonquakes to picosecond processes of nonradiative decay of excitational energy in molecules. The intense and powerful beam of coherent radiation capable of concentra-... 

V. S. Letokhov My answer to Prof. Quack is that it is indeed difficult to predict theoretically the effect of intense femtosecond IR pulses on the IVR rate of polyatomic molecules, which is important for the transfer of vibrationally excited molecules from low-lying states to the vibrational quasi-continuum. We are developing the relevant theoretical mechanisms of IR MP E/D of polyatomics since the discovery of this effect for isotopic molecules BC13 and SF6 in 1974-1975.1 hope that it will become more realistic to study experimentally the influence of intense IR pulses on IVR due to the great progress of femtosecond laser technology. 

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