Efficient electro-optic sampling detection of terahertz radiation via Cherenkov phase matching

Abstract

We experimentally demonstrate an efficient electro-optic sampling scheme based on Cherenkov phase matching of broadband terahertz radiation with 800-nm femtosecond probe beam in a 0.5 mm-thick LiNbO3 crystal coupled to a Si prism. The electro-optic signal from a Cherenkov-phase-matched LiNbO3 crystal is found to be comparable to that with a 4 mm-thick ZnTe crystal using a collinear phase matching. The Cherenkov phase matching technique can be achieved with any probe wavelength and hence has an advantage over the collinear phase matching method.

Enhancement of THz EO sampling efficiency using waveguides

“…1) is similar to that used in Ref. [2] for Cherenkov phase-matched EO sampling of THz radiation except that the Si-prism/LN was replaced with the structure shown in Fig. 2, A femtosecond laser (780 nm wavelength, 150 fs pulse width, and 50 MHz repetition rate) was used as a pump and probe light source.…”

“…Recently, we have proposed and demonstrated the Cherenkov-phase matched EO sampling using a Si-prism coupled LiNbO 3 (LN) crystal (Si-prism/LN) [1,2]. The Cherenkov-phase matched EO sampling enables one to use EO crystals, such as LN, with a large velocity mismatch between optical and THz waves and can be used with any optical sampling wavelength.…”

Terahertz Pulse Detection Techniques and Imaging Applications

“…(vi) Some work is related to adapting photoconductive THz detectors to THz-TDS systems [31,32]. As for EO sampling, similarly, there are various progress such as improvement of detection eiciency [33,34] and dynamic range [35], polarization sensing of THz pulses [36] and a new detection scheme based on the amplitude variation of optical pulse [37].…”

Detection of Terahertz Pulsed Radiation by Using Heterodyne Electro‐Optic Sampling Scheme

“…In this study, we report our results obtained for heterodyne EO sampling in case of noncollinear Cherenkov phase matching [4]. In the next section we explain the principle of heterodyne EO sampling, and LiNbO 3 (LN) is considered as an example of an EO crystal in Section 3.…”