Measurement of Minority Carrier Lifetime Using Open-Ended Waveguide: Transmission Method

The letter initially investigates variations in waveguide antenna insertion loss (S21) under laser-onand laser-offstates across multiple frequency bands. Terahertz point-frequency measurements at 109, 164, and 235 GHz were performed using a vector network analyzer to characterize S21attenuation, thereby validating the feasibility of carrier lifetime extraction via transmission-mode methodology. Comparative analysis of$\Delta $S21across bands preliminarily indicates enhanced system sensitivity at higher frequencies. This work introduces the microwave photoconductive transmission method, for the first time, for minority carrier lifetime measurement in the terahertz bands. Experiments confirm its enhanced sensitivity at these frequencies; the transmission mode also extends applicability to a wider range of samples.