Electrooptical generation and detection of femtosecond electrical transients

Recent work on the generation of ultrashort electrical pulses by optical rectification of femtosecond optical pulses in electrooptic materials is summarized. This technique, which is called electrooptic Cherenkov radiation, is described in detail with particular emphasis on the effects of dispersion due to coupling to lattice vibrational resonances. Recent experimental results in lithium tantalate are described which illustrate these effects. When the duration of the exciting femto second optical pulse is comparable to the period of the lattice vibrations, a pronounced ringing is observed in the electrical waveforms. A coupled oscillator model is used to develop a theory that accurately accounts for these effects and can be used to predict the limiting speed of response and generation efficiency of different electrooptic materials.<>