This invention belongs to the field of distributed
optical fiber sensing technology and relates to a method for synergistic suppression of
phase noise and
distortion in optical
frequency domain reflection using coded differential methods. The method includes: acquiring upper and lower sweep beat frequency signals; separating the upper and lower sweep beat frequency signals to obtain an upper sweep beat frequency
signal and a lower sweep beat frequency
signal; acquiring the upper and lower sweep beat frequency electrical signals; delaying the upper sweep beat frequency electrical
signal by a spatial resolution and then mixing it with the lower sweep beat frequency electrical signal, or delaying the lower sweep beat frequency electrical signal by a spatial resolution and then mixing it with the upper sweep beat frequency electrical signal, to obtain a mixed signal with
phase noise and
frequency domain distortion suppressed, and analyzing the Fourier
frequency domain spectrum of the mixed signal. This invention also provides a
system for synergistic suppression of
phase noise and
distortion in optical frequency domain reflection using coded differential methods, including a positive and negative double-
sideband sweep frequency acquisition device, a
beam splitter, a
spread spectrum device, an interferometer, a beat frequency
signal acquisition device, and an electrical
delay unit. This invention can effectively suppress phase
noise and frequency domain distortion
noise.