Programmable Pulse Bursts for Terahertz Spectroscopy by using Bolometric only Detection

Abstract

The generation of high-energy Terahertz (THz) pulses via optical rectification (OR) in Lithium-Niobate and organic crystals serves as an attractive route for applications such as nonlinear THz spectroscopy, single-shot THz imaging, and THz radar. Being generated by broadband near-infrared (NIR) driver pulses, OR-generated pulses typically feature sub-THz bandwidths, or higher, often substantially broader than narrow resonances of the sample. We report on our recent progress in utilizing the generation of microjoule-level THz pulses, by driving OR with a burst of closely spaced NIR pulses. By adjusting the pulse number and spacing in the burst we control over central THz frequency of equidistant narrowband spectral peaks. The spectral tunability in combination with a conventional bolometric detection allows selective detection of narrowband resonances of particular organic samples.