Laser induced gratings in CdS

Transient gratings are produced in CdS by single photon absorption of a Nd-YAG laser interference pattern at 530 nm. The gratings are detected by Bragg diffraction of a dye laser beam at 595 nm. For a 1 cm thick crystal a diffraction efficiency of 25% and depletion of the primary laser power down to 50% is observed with an incident Nd-YAG laser energy density of 70 m Ws/cm2 and 18 ns pulse width. The decay of the grating is measured using 40 ps mode-locked Nd-YAG laser pulses and is given by different processes with decay times ranging from 5 ns to 50 μs depending on temperature varying from 10 to 300 K. At 300 the decay times of the gratings agrees with the decay times of a luminescence band at 712 nm.