Optical Kerr gate measurements

FIGURE 49.8. Schematics of experimental arrangement of the optical Kerr gate measurement. 

Contrary to the above-described detection methods, fluorescence up-conversion and optical Kerr gate techniques readily achieve picosecond/femtosecond time resolution (Ippen and Shank 1975 Shah 1988 Takeuchi and Tahara 1998), because they are in the pump-probe measurement, in principle. 

The Optical Kerr Gate (OKG) method allows measurement of x by studying the polarization change of a probe beam, propagating through the system where the optical birefringence is induced through an intensity-dependent refractive index. The method was described by Ho [69]. 

To study the carrier and vibrational relaxation dynamics, mode-locked laser systems, which provide femtosecond pulses and fast and sensitive detection systems are necessary. For detection, streak cameras are used for measurements with time resolution in the subpicosecond range or CCD cameras for time-integrated measurements. For the latter, time resolution can be achieved by using optical Kerr gates or upconversion [266,268]. In general, the two mainly used optical detection mechanisms for coherent phonons (optical, acoustical, or LO-plasmon coupled modes) are the pump/probe [280-285] and the four-... 

Optical Kerr Gate and Pump-Probe Measurements... 

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