Sensors, Vol. 19, Pages 5264: The Effect of Light Source Line Width on the Spectrum Resolution of Dual-Frequency Coherent Detection Signals

Sensors, Vol. 19, Pages 5264: The Effect of Light Source Line Width on the Spectrum Resolution of Dual-Frequency Coherent Detection Signals Sensors doi: 10.3390/s19235264 Authors: Ren Sun Zhang Zhao In this paper, the power spectrum resolution problem of dual-frequency coherent mixing signals is analyzed when the Doppler frequency difference is small. The power spectrum function formula of the four optical coherent mixing signals is obtained using statistical theory and the Wiener–Khinchin theorem. The influence of delay time and light source line width on the power spectrum of dual-frequency coherent signals is analyzed using this formula. The results show that delay time only affects the peak of the power spectrum of the coherent signal. An increase in the line width of the light source broadens the signal power spectrum and reduces the peak value. The necessary condition for distinguishing the Doppler frequency difference is that the theoretical Doppler frequency difference is greater than 1/5 times the line width of the light source.
Source: Sensors - Category: Biotechnology Authors: Tags: Article Source Type: research