Temporal shape

The peak surface temperature under the center of the laser beam is 990 C above the starting surface temperature. The detailed temporal shape of the surface temperature will depend on the detailed time profile of the laser pulse. However, two Important characteristics of the temperature jump which is generated will be retained ... 

To introduce the application of ultrashort laser sources in microscopy, we want to review some properties of femtosecond pulses first for a comprehensive introduction the reader may refer to one of the established textbooks on femtosecond lasers (Diels and Rudolph 2006). The most important notion is the Fourier transform relation between the temporal shape of a pulse and the spectrum necessary to create it. This leads to the well-known time-bandwidth product for the pulse temporal width (measured as full width at half maximum, FWHM) At and the pulse spectral width Av. 

Therefore, the spectral phase v) and consequently the group delay GD(v) for each color controls the temporal shape of the pulse. These important relations are summed up in Figure 7.4. 

Dual to prediction in time domain (with the result of flattening the spectrum of the residual), applying a filtering process to parts of the spectrum has been used to control the temporal shape of the quantization noise within the length of the window function of the transform [Herre and Johnston, 1996],... 

The temporal shapes of the SIFE and SOKE signals may be described by a convolution of the probe intensity envelope with evolution functions for the sample polarisation, as discussed in the previous section. This transient polarisation results from optical orientation of electronic linear and angular momentum and decays on timescales of tens of femtoseconds. Differences... 

In the degenerate four wave mixing (DFWM) experiment the third-order susceptibility 3)(-tt>,tt>,-CL>,CL>) with degenerate frequencies can be determined [22]. This nonlinear susceptibility is directly proportional to the nonlinear refractive index n2, which is used to describe optically induced refractive index changes. An advantage of this technique is the possibility to record the temporal shape of the third-order nonlinear optical signal. 

KB Konstantinov and T Yoshida. Real-time qualitative analysis of the temporal shapes of (bio)process variables. AIChE J., 38(11) 1703-1715, 1992. 

The goal of the optimal control strategy described here is to optimize temporal shapes of phase-unlocked pump and dump pulses (i.e., pump and dump pulses)... 

A second important observation is that the temporal shape of the emission rise follo vs a step function. This is demonstrated in Fig. 11.8. It sho vs the results of fitting an exponential increase convoluted with the crosscorrelation (a), a delayed step like rise convoluted with the crosscorrelation (b) and the complete model function (c) to an experimental trace of HBT at a probe wavelength of 564 nm where the oscillatory contributions are quite weak. The exponential increase and the delayed step function give almost the same ESIPT time [33]. However, the exponential increase deviates significantly from the data at short delay times whereas the step function matches quite accurately the essential shape of the trace. 

MPD yields of CF2HCI. The effects are most pronounced at low values of the laser fluence (and hence for the pulses of constant temporal shapes used, of the laser intensity) and is illustrated for the electric field in Figure 4. Breakdown of the... 

Calculation of CBF requires measurement of the temporal shape of both the arterial input and the tissue time-density curves [114, 124], The true input into the tissue voxel of interest cannot be measured directly in practice, the AIF is estimated from a major artery (e.g., the MCA or the top of the internal carotid artery), with the assumption that this represents the exact input to the tissue of interest. Any delay or dispersion of the bolus introduced during its passage from the artery used for AIF estimation to the tissue of interest will introduce errors in quantification of CBF [125,126]. 

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