Performance analysis of tabletop single-pulse terahertz detection at rates up to 1.1 MHz

Standard terahertz time-domain spectroscopy uses a relatively slow multidata acquisition process that has hindered the technique's ability to resolve ``fast'' dynamics occurring on the microsecond timescale. This timescale, inaccessible to most ultrafast pump-probe techniques, hosts a range of phenomena that has been left unexplored due to a lack of proper real-time monitoring techniques. In this work, chirped-pulse spectral encoding, a photonic time-stretch technique, and high-speed electronics are used to demonstrate time-resolved terahertz detection at a rate up to 1.1 MHz. This configuration relies on a tabletop optical source and a setup able to resolve every terahertz transient generated by the same source. We investigate the performance of this single-pulse terahertz detection system at different acquisition rates in terms of experimental noise, dynamic range, and signal-to-noise ratio. Our results pave the way towards single-pulse terahertz time-domain spectroscopy at arbitrarily fast rates to monitor complex dynamics in real time.