Analysis of terahertz pulse measurement with a chirped probe beam

In this letter, terahertz (THz) pulse measurements with a chirped probe pulse are analyzed. The method of stationary phase is used to explore the relation between the temporal waveform of an input THz pulse and spectral distribution of an output probe pulse on a detector array. The dependence of the temporal resolution on the chirp rate, the spectrum of the chirped probe beam, and the spectral resolution of the spectrometer is discussed. We confirm that the temporal resolution of the chirped pulse technique is equal to the square root of the product of the original unchirped probe pulse duration and the chirped pulse duration. (C) 1998 American Institute of Physics. [S0003-6951(98)03743-7].