Windowed Fourier method based on phase compensation in heterodyne detection

Optical heterodyne detection technology is a high-precision detection technology, which is an extension of microwave heterodyne technology in the optical band [1]. Compared with direct detection technology, which can only obtain signal strength information, heterodyne detection technology can obtain the signal from intermediate frequency signals [2]. All information of the frequency, phase and amplitude of the measured signa [3]l, which makes this detection method have many advantages such as high sensitivity and good selectivity [4-5]. In heterodyne detection, the matching state of the local oscillator light field and the signal light field determines the detection sensitivity of the heterodyne detection system [6-7]. This paper proposes a new phase compensation method by pushing the theoretical formula. Reduce the influence of external noise on heterodyne detection. The positioning error is greatly reduced by the proposed phase compensation. The stability of the method is proved through repeated experiments. Repeated experiments proved that the method reduces the deviation from6.289 to 3.814. It provides a new practical idea for the application field of active optical heterodyne detection to solve the problem of decoherence effect of heterodyne signals.