提出了一种返波管频率稳定性快速检测方法。利用一个抛物面镜对返波管辐射信号进行收集和准直，然后将探测器放置在准直平行光束的后方进行检测，并使所测信号经示波器显示和读出。根据法布里-珀罗干涉原理估测返波管的单频频率输出稳定性。本文方法对于提高基于返波管的频域高分辨率太赫兹波谱系统的性能具有重要的应用价值。

A fast method for detecting the frequency stability of Back Wave Oscillators (BWOs) is proposed. The radiation from a BWO is collected and collimated by a parabolic mirror and is detected by a fast terahertz detector at the other end of the collimated light beam. The measured signal is displayed and recorded via an oscilloscope. Finally, the single-frequency output stability of the BWO is estimated according to the Fabry-Perot interference principle. The method proposed is of important application value to the performance improvement of frequency-domain terahertz spectroscopy systems with high frequency resolution.