Self-referenced spectral domain interferometry for improved signal-to-noise measurement of terahertz radiation.

In this work, we demonstrate self-referenced spectral domain interferometry for the electro-optic sampling of terahertz (THz) electric fields. This technique allows reduction of the phase noise of the measurement, thus increasing the signal-to-noise ratio (SNR). Using the proposed technique, we achieve a more than sixfold improvement in the SNR of the detected THz electric field.