TRTS Setup

The time-resolved THz spectrometer (TRTS) is shown. A Spectra Physics regenerative amplifier system (Millennia-Tsunami-Merlin-Spitfire) produces a 1 kHz pulse train of 1mJ, 800 nm pulses of 100 fs duration. This beam is split into three portions, one used for THz generation via optical rectification in a <110> ZnTe crystal. Another for THz detection via free-space electro-optical sampling in another <110> ZnTe crystal. And the third is used to photoexcite the sample. The THz is focused onto the sample, which could be place in a cryostat, and collinearly propagated with the visible pump pulse. The chopper modulates either the THz generation beam, or the visible pump beam depending on whether a reference scan or a photoexcitation scan is being collected, respectively.

There are three variable delay lines (only two are needed for any particular experiment). Either delay lines 1 and 3 are scanned or delay lines 3 and 2. A typical THz reference scan is shown in panel (a) with its corresponding power spectrum in panel (b). The pulses have usable bandwidth from 10 to 90 cm^-1 and have a signal-to-noise ratio of over 1000:1.