Laser profile

Figure 4. Laser Profile of Dented Steam Generator Tube...

Figure 5.11 shotvs the temporal profile of the intensity change in the SFG signal at the peak of the Vco mode (2055 cm ) at OmV induced by visible pump pulse irradiation. The solid line is the least-squares fit using a convolution of a Gaussian function for the laser profile (FWFJ M = 20 ps) and a single exponential function for the recovery profile. The SFG signal fell to a minimum within about 100 ps and recovered... 

Nanosecond flash spectroscopic studies showed that II fluoresces in CH2CI2 and ethanol solutions at room temperature. The emission has a lifetime less than 1.0 nsec in either solvent and cannot be resolved from the laser profile. Quantum yield of... 

Gaussian Laser Profile-Voigt Atom Profile. This case turns out to be a better approximation of our experimental situation, i.e., the laser FWHM is fairly broad compared to the absorption line width and the absorption profile of atoms in an atmospheric combustion flame is described by a Voigt profile. Here the laser is assumed to have a Gaussian spectral profile as well as a Gaussian atomic absorption profile. In this case, convolution of two Gaussian functions is still a Gaussian function. Evaluation of the ratio n2/nT, and the fluorescence radiance. Bp, allows determination of the half width of the fluorescence excitation profile, 6X... 

The spatial and temporal modifications of the laser profile during propagation are calculated for the case of a negatively chirped 42-fs pulse with 5-mJ energy. The gas medium is a 9-mm Ne gas jet with a density of 1.4xl018cm 3. 

The laser beam profile at the end of the medium can be direct evidence of the profile flattening. Figure 8.6b and c shows the laser profiles at the gas jet positions z = 0 and z = —18 mm. At z = 0, the laser profile was severely distorted and weakened after the propagation. On the other hand, at z = —18 mm, the laser beam formed a flattened profile with a radius of 60 pm, which closely matched the 3-D calculation. It is thus clear that a proper selection of the gas jet position is critical for the profile flattening and self-guiding of laser pulses. 

Figure 3.10 The b t),bo t), and fcjW expansion coefficients (Eqs. (70,76, and 79)) as functions of time and energy for the EIT line shape and laser profile of Figure 3.8.

The 3D laser image system is mounted at the back of a vehicle that usually carries an inertial profilometer at the front. Figure 16.36 shows a sample of three different 3D laser profilers. 

TSD is an articulated truck with a rear axle load of 100 kN (22 kips) that uses Doppler lasers mounted on a servo-hydraulic beam to record the deflection velocity of a loaded pavement. The number of Doppler lasers in the first TSD devices was four, while in the second-generation TSD devices, seven Doppler lasers are used (Figure 16.54). Flowever, it has been reported that the device delivered to South Africa in 2013 had 10 lasers and included laser profiling and right-of-way imaging (Greenwood Engineering A/S). 

Correction of simple laser-induced broadening effects may not be necessary if the resolution of the spectrograph is three or four times lower than the laser bandwidth. If this is not the case and no other steps to correct for the laser profile are attempted, the long-term stability of any model will depend greatly on the consistency of the laser profile. Because some lasers exhibit unusual profiles in an inconsistent manner, repeatability is... 

NIR (near IR) FPAs—for telecommunications, fiber optic, and laser-profiling... 

Fig. 8,24, Overlap between a multimode laser profile and two Doppler-broadened molecular absorption lines...

Finally, a good characterization of the laser spot on the surface is important for creating protein patterns. Since patterns are made by a sequence of lines defined by the movement of the laser, the spacing between such lines must be carefully chosen. Furthermore, since the spatial concentration profile follows the laser profile, which is usually Gaussian or bell-shaped, an adequate distance can minimize concentration ripples and undesired fluctuations within the pattern area. 

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