Laser-pulse energy requirements

Laser-Pulse Energy Requirements for the Single Shot Experiment... 

The statistical nature of the turbulent flame required the analysis of many temperature and density data points from separate pulses for accurate results. Thus, an overall computer system was used to control the various components of the combustion probe apparatus, and to collect and interpret the resultant data in an accurate and timely fashion. This system produced a block of data for each laser shot that included information about the Raman signals, LV readings, and ancillary data such as an identifying shot number and corresponding dye laser pulse energy. Typical current operation permits about twenty experimental run conditions daily, with up to several hundred shots per run. 

Chiu et have indicated a potential source of error in measurements of laser pulse energy in i.r. photochemical experiments. They stress the importance of determining the transmission of any attenuation filters used in experiments at the laser intensities for which they are required. 

Novel polymer systems with much enhanced TPA initiators have been synthesized. However, it is still attractive to use well-known systems that were developed for conventional UV polymerization due to their excellent chemical, physical, and mechanical properties. Initiators in these resins generally have small TPA cross-sections, which require very high laser pulse energy for two-photon use. A strategy for circumventing this situation is to induce photopolymerization not by direct TPA of initiators, but by TPA-induced up-conversion fluorescence. An efficient fluorophore that emits at blue or shorter wavelengths was doped into resin. By TPA, the excited fluorescence polymerizes the resin by a single photon process. Since the fluorescence was three-dimensionally confined at the focal spot, the polymerization was also restrained to occur at this volume. 

SFIG or SFG from a medium that has a strong response in a separate detection anu. By this means, one may fiilly compensate for variations not only in pulse energy, but also in the temporal and spatial substructure of the laser pulses. Some experiments may require measurement of the phase of the nonlinear signal [57]. 

Femtosecond filamentation is a universal phenomenon observed in gases, liquids, and solids when the photon energy of incident laser pulse is smaller than the lowest energy required to achieve electronic excitation. There are... 

MeV required in proton-therapy for an effective treatment of deep seated tumors [26]. Fuchs and co-authors have proposed a scaling law [27], allowing the necessary laser parameters to produce proton beams of interest for such applications to be estimated. In their work, best suited to hundreds of fs/some ps duration laser pulses, they use the self-similar fluid model proposed by Mora [28] giving the following estimate for the maximum FWD proton energy ... 

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