PIEZOELECTRIC OSCILLATIONS IN PLZT PYROELECTRIC DETECTORS IN RESPONSE TO SHORT CO2-LASER PULSES

Piezoelectric (PZE) oscillations superimposed on the pyroelectric (PRE) voltage response to short (<50 nsec) single CO2 laser pulses in PLZT detectors are shown to have an incubation time, i.e., to start after the beginning of the PRE response. During the incubation time (40-60 nsec, depending on sample geometry) the PRE response is not disturbed, thus PRE detectors for use with short ir pulses can be designed with minimum PZE interference. The initial PZE amplitudes were 0.05-0.4 of the observed peak PRE voltages. The periods of the PZE oscillations with the measured lengths of the samples gave 2.2 km/sec for the velocity of sound in PLZT.