Terahertz electro-optical detection: optical phase or energy measurements

摘要: Models of different available single-photodetector electro-optic sampling schemes are considered from the unified theoretical position. It is taken into account that under terahertz wave detection, not only do polarization states femtosecond optical pulse components change but modules their amplitudes also varied. As a result, information concerning can be obtained using conventional ellipsometry readout scheme (probe-phase sampling) by simple measuring induced power pulses (probe-energy sampling). Spectral sensitivities both these methods calculated for cases nonlinear-optical crystals with zinc-blende symmetry (like ZnTe) and one active component second-order susceptibility tensor PPLN). found ratio between spectral pure probe-phase probe-energy proportional to frequencies in all types crystals. shown signal near-zero transmission point scheme, which best imaging, has mixed character. While contribution sensitivity appears due spatially nonuniform residual birefringence nonlinear crystal, part uniform distribution increased angle misalignment element.