Linear chirping

The laser frequency is a combination of three linear chirping ... 

The second example is the quadratically chirped pump-dump scheme. Since the pioneering work by Tannor and Rice [119], the pump-dump method has been widely used to control various processes. However, since it is not possible to transfer a wave packet from one potential energy surface to another nearly completely by using the ordinary transform limited or linear chirped pulses, the... 

Figure 1. Temporal profiles and relative intensities of the generated SH pulses calculated for several values of focusing strength m = L/b, and ratio LjL, = 40 for (a) uniform (periodically-poled) nonlinear media and (b) linearly chirped (aperiodically-poled) quasi-phasematched grating with AA = 0.2 /um (d = 10.3 ) The fundamental pulse shape (grey...

Following the previously described method we obtain an expression for the SH amplitude, S L, p), at the output of a nonlinear media with linearly chirped (aperiodically-poled) quasi-phase-matched (QPM) grating ... 

The theoretical model of SHG with focused beams in both homogeneous and linearly-chirped aperiodically-poled structures predicts very well the results from the bulk KNbOs and bulk appKTP crystals. The model of SHG in the two waveguide crystals explains qualitatively the saturation and... 

Fig. 6.2. Illustration of the frequency-time dependences of pump and Stokes pulses in three different CRS excitation pulse schemes and their corresponding spectral resolution of Raman shifts. A Using a pair of transform-limited femtosecond pulses of broad spectral and narrow temporal widths results in a broad bandwidth of Raman shifts that exceeds the line width of a single Raman resonance. B Using transform-limited picosecond pulses of broad temporal and narrow spectral width readily provides high spectral resolution matching the Raman resonance line width to be probed. Selection of a Raman resonance shifted by AQr is achieved by tuning the frequency of one of the laser beams by the same amount. C Spectral focusing of a pair of identically linear chirped pump and Stokes femtosecond pulses results in a narrow instantaneous frequency difference in the CRS process, thus also providing narrow-bandwidth CRS excitation. Selection of a Raman resonance shifted by AQr is achieved by adjusting the time delay At between the pulses. Shifted pulses in (B) and (C) are depicted hatched...

Fig. 7.6. The time-of-flight mass spectra of the ion species recorded when ethanol molecules are irradiated with intense laser pulses. The strong peak appearing at rn/q = 18 is ascribed to the residual water molecules existing in the vacuum chamber. The linear chirp rates of the laser pulses are a 1.6 x 10 2ps2, b 0 (transform limit), and c —1.6 x 10 2ps2 [13]...

Fig. 7.10. Evolution of cost function during iterative control by manipulating individual 128 segments of the SLM. The optimized ion yield ratio is roughly as same as that obtained by varying the linear chirp rate...

The temporal characteristics of chirped laser pulses can be quantitatively analyzed in terms of linear chirp coefficient and pulse duration. The linear chirp coefficient, a, is defined as the second derivative of the temporal... 

Fig. 8.4. a Linear chirp coefficient and b pulse duration of chirped laser pulses with respect to the grating detuning of a pulse compressor... 

One might expect that linearly chirped pulses are sufficient to ladder climb Morse potentials, because the slope of the chirp can be adjusted to match the anharmonic spacing of the Morse potential (the frequency difference between... 

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