Bow-Tie Cavity for Terahertz Radiation

TL;DR

This paper presents the development and testing of a bow-tie resonant cavity for terahertz radiation, achieving high finesse and quality factor, with detailed theoretical and experimental analysis.

Contribution

It introduces a novel bow-tie cavity design for THz radiation with improved performance metrics and comprehensive theoretical and experimental evaluation.

Findings

Measured finesse F=123

Quality factor Q=5.1x10^5

Good agreement between simulated and experimental spectra

Abstract

We report on the development, testing, and performance analysis of a bow-tie resonant cavity for terahertz (THz) radiation, injected with a continuous-wave 2.55 THz quantum cascade laser. The bow-tie cavity employs a wire-grid polarizer as input/output coupler and a pair of copper spherical mirrors coated with an unprotected 500 nm thick gold layer. The improvements with respect to previous setups have led to a measured finesse value F=123, and a quality factor Q = 5.1x10^5. The resonator performances and the relevant parameters are theoretically predicted and discussed, and a comparison among simulated and experimental spectra is given.