Terahertz-Wave Vibrometer Using a Phase-Noise-Compensated Self-Heterodyne System

A terahertz (THz) vibrometer based on a photomixing self-heterodyne system for measuring the vibration of an object behind an opaque barrier is reported. The proposed THz vibrometer employs a phase noise compensation technique to reduce the phase noise of the system and thereby improves the signal-to-noise ratio (SNR) of the system. In this letter, the performance of THz vibrometers with and without the phase noise compensation technique is compared. The proposed THz vibrometer employing a phase noise compensation technique shows an improved SNR and larger bandwidth compared with those of the conventional THz vibrometer using a Golay cell.