Chirped optical beam electro-optically measures terahert¥pulses

A grou¥at Rensselaer Polytechnic Institute (Troy, NY) has used a linearly chirped optical probe pulse in a free-space electro-optic detection system to measure the temporal waveform of a terahert¥pulse and has demonstrated a single-shot (single pulse) coherent measurement of such a pulse. X.-C. Zhang and Zhiping Jiang copropagated a chirped optical probe pulse (820 nm and 30 ps long) and a terahert¥pulse through a zinc telluride (ZnTe) crystal. Polarization of different spectral comp

Mar 1st, 1998

Chirped optical beam electro-optically measures terahert¥pulses

A grou¥at Rensselaer Polytechnic Institute (Troy, NY) has used a linearly chirped optical probe pulse in a free-space electro-optic detection system to measure the temporal waveform of a terahert¥pulse and has demonstrated a single-shot (single pulse) coherent measurement of such a pulse. X.-C. Zhang and Zhiping Jiang copropagated a chirped optical probe pulse (820 nm and 30 ps long) and a terahert¥pulse through a zinc telluride (ZnTe) crystal. Polarization of different spectral components of the chirped pulse was rotated by a different portion of the terahert¥pulsed field by the Pockel`s effect. Using an optical analyzer, the polarization modulation was converted to the amplitude modulation, and a grating-lens combination was used to disperse and focus the collimated probe beam on a linear diode array (which had 1024 pixels). By measuring the spectrum difference of the probe beam with and without pulsed electromagnetic field modulation, a temporal measurement of the terahert¥waveform was obtained without a moving element (such as a mechanical translation stage) for the time delay. This differential distribution reconstructs both amplitude and phase of the terahert¥pulse.

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