Performance analysis of table-top single-pulse terahertz detection up to 1.1 MHz

Abstract

Slow data acquisition in terahertz time-domain spectroscopy (THz-TDS) has hindered the technique's ability to resolve "fast" dynamics occurring on the microsecond timescale. This timescale, arguably too slow to be accessed via standard optical pump-probe techniques relying on ultrafast sources, 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 THz detection at a rate up to 1.1 MHz. This configuration relies on a table-top source and a setup able to resolve every THz transient that it can generate. We investigate the performance of this 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 THz-TDS at arbitrarily fast rates to monitor complex dynamics in real-time.