Study on High-Precision Optical Signal Detection Based on the Weak Measurement Method

Spectral analysis technology in optical signal detection can obtain the spectral characteristics of matter according to the wavelength or frequency information of the optical signal. Commonly used spectral analysis techniques include grating spectrometer, Fourier transform infrared spectrometer (FTIR), Raman spectrometer, etc. In order to improve the measurement of optical signal, due to the limitation of detector detection bandwidth and system noise and external interference, this paper proposes an optical signal estimation scheme based on weak measurement method. Moreover, compared with the original weak measurement scheme, the detection time of the new scheme proposed in this paper breaks through the limitation of Nyquist sampling theorem, has the performance advantage of resisting aliasing interference, and can effectively improve the signal-to-noise ratio of the system by extending the detection time. This paper presents a new weak measurement theory scheme for optical signals. Theoretical research studies show that the scheme can estimate the amplitude and phase of the optical signal and recover the time domain by setting the dynamic phase factor with time for the previous or post-selection process. Because the detection time of the scheme is not limited by the Nyquist sampling theorem, the new scheme has the performance advantage of anti-aliasing interference, which effectively solves the limitation of the detector detection bandwidth in the original scheme.