Spectrum Intensity Ratio Detection for Frequency Domain Weak Measurement System

The traditional method of frequency domain weak measurement has a lot of noise. In this paper, we analyze the 2000 curves obtained by experiments and get the conclusion that the signal-to-noise ratio will increase with the increase of signal strength. We simulated the 252 curves produced by the phase change and used this to fit the relationship between the original calculation method and our spectral height ratio (HR) method. Through previous experimental data verification, our method can greatly reduce the system noise of the dual-mode working area in the frequency domain weak measurement. At present, universal frequency domain weak measurement and measurement system have received increasing attention. In this paper, we introduce a frequency domain weak measurement with spectrum height ratio (HR) that can greatly reduce the system noise in the frequency domain weak measurement bimodal work area. Moreover, we completed comparative experiments on a total internal reflection weak measurement system. The experimental results show that the system resolution obtained by using the HR method is 6.33 × 10
^-7
RIU, which is an order of magnitude higher than that of the conventional center wavelength offset algorithm which is commonly used in weak frequency measurement.