Autocorrelation signals

Figure B2.1.3 Output of a self-mode-locked titanium-sapphire oscillator (a) non-collinear intensity autocorrelation signal, obtained with a 100 pm p-barium borate nonlinear crystal (b) intensity spectrum.

The frill width at half maximum of the autocorrelation signal, 21 fs, corresponds to a pulse width of 13.5 fs if a sech shape for the l(t) fiinction is assumed. The corresponding output spectrum shown in fignre B2.1.3(T)) exhibits a width at half maximum of approximately 700 cm The time-bandwidth product A i A v is close to 0.3. This result implies that the pulse was compressed nearly to the Heisenberg indetenninacy (or Fourier transfonn) limit [53] by the double-passed prism pair placed in the beam path prior to the autocorrelator. 

Figure 8.1c shows the interferometric autocorrelation signal of second harmonic generation (SHG) from a BBO crystal positioned at the sample plane of the microscope. The shape of the SHG trace was symmetrical with respect to the time origin the ratio of the maxima to the background was 8 1, indicating that nearly ideal... 

V. Extension to Heterodyne-Detected Four-Wave Mixing Appendix A Time- and Frequency-Gated Autocorrelation Signals Appendix B The Signal and the Optical Polarization... 

Substituting (2.12) into (2.7), we obtain the autocorrelation signal (2.5), where the bare signal is given by... 

We have thus expressed the autocorrelation signals using the Wigner representation for both the external fields and the gate. The molecular properties are contained in the response function F(4). In the next section, we show how when the incoming external pulses and the detection gate are temporally well separated, we can use the Wigner representation for the material system as well. 

This formula resembles Eq. (2.6) for the autocorrelation signal. We can further expand 5(l)( ,r) to second order in the pump field and express the result in terms of the four-point correlation function (2.8) (see Appendix E). 

APPENDIX A TIME- AND FREQUENCY-GATED AUTOCORRELATION SIGNALS... 

In Fig. 6.74 the power density spectrum and the interferometric autocorrelation signal of a femtosecond laser pulse is compared. 

Fig. 6.73 Autocorrelation signal SocG (r) for different pulse profiles without background suppression (upper part) and with background suppression (lower part) (a) Fourier-limited Gaussian pulse (b) rectangular pulse (c) single noise pulse and (d) continuous noise...

In Fig. 6.75b, the upper and lower envelopes of the autocorrelation signal are plotted as a function of the normalized delay time r I AT for different values of the chirp parameter a in (6.47) [775]. 

Fig. 11.47a-d. Autocorrelation signal S oc for different pulse profiles without... 

In the off-resonant regime at 760 nm, the Ufetime is about 0.5 ps, rising to more than 2 ps at 680 nm (Fig. 9.50). As with DFWM measurements, the lifetime can not be seen as an exponential signal decay, but as a broadening of the laser pulse autocorrelation signal. The lifetime... 

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