Patent ID: 11867540
Assignee: GUANGDONG BRILLINNOVA TECHNOLOGY CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A Brillouin optical time domain reflectometer with an ultra-high spatial resolution based on bipolar differential phase encoding, comprising:
a narrow-linewidth laser configured to emit a linear polarized laser;
a polarization maintaining coupler configured to divide the linear polarized laser into light of two paths of light, wherein the light of one path is transmitted to a Mach-Zehnder modulator for phase modulation, and the light of the other path is transmitted to a coherent optoelectronic receiver as a local oscillator light source;
a differential encoder configured to perform differential encoding on an original encoding sequence, wherein the original encoding sequence comprises a first encoding sequence and a second encoding sequence, the first encoding sequence and the second encoding sequence are two groups of encoding sequences, and polarities thereof are opposite to each other;
the Mach-Zehnder modulator configured to perform phase modulation on a phase of the linear polarized laser based on an encoding sequence obtained by the performing differential encoding on the original encoding sequence, and output an optical pulse;
an optical circulator and a sensing fiber, wherein the optical circulator is configured to input the optical pulse into the sensing fiber, and receive Brillouin scattering light returned by the sensing fiber;
the coherent optoelectronic receiver configured to perform optoelectronic mixing coherent receiving on the local oscillator light source and the Brillouin scattering light, to obtain a microwave signal, wherein the microwave signal comprises a Stokes signal and an anti-Stokes signal;
a sideband demultiplexer configured to perform signal separation of the Stokes signal and the anti-Stokes signal in the microwave signal, and send the Stokes signal and the anti-Stokes signal to a result measurement module; and
the result measurement module configured to calculate a first instantaneous frequency and a second instantaneous frequency respectively based on the Stokes signal and the anti-Stokes signal, and configured to calculate a final measurement result based on the first instantaneous frequency and the second instantaneous frequency.