Optical time-domain reflectometry signal detection method and apparatus
The present invention provides an optical time-domain reflectometry signal detection method, including the following steps: modulating, under the control of a correlation code pattern sequence respectively, n detection optical signals transmitted by detection light sources of different wavelengths into n pulse optical signals, where n is a natural number greater than or equal to 2; combining the n pulse optical signals and outputting a detection optical signal to an optical fiber under test; receiving a backscattered optical signal from the optical fiber under test and dividing the backscattered optical signal into n optical signals according to wavelengths; and performing correlation processing on the n optical signals according to the correlation code pattern sequence and outputting a correlation optical time-domain reflectometry signal. The present invention further provides an optical time-domain reflectometry signal detection apparatus.
1. An optical time-domain reflectometry signal detection apparatus, comprising n detection light sources of different wavelengths, and n modulators, a multiplexer, a coupler, a demultiplexer, a correlator, and a code pattern generator, wherein n is a natural number greater than or equal to 2, and wherein
the code pattern generator is configured to generate a correlation code pattern sequence, and input the correlation code pattern sequence to the n modulators and the correlator;
each of the modulators is configured to modulate a detection optical signal transmitted by a corresponding detection light source into a pulse optical signal;
the multiplexer is configured to combine n pulse optical signals transmitted by the n modulators and output a detection optical signal;
the coupler is configured to perform directional coupling on the detection optical signal output by the multiplexer and send the detection optical signal output by the multiplexer to an optical fiber under test; and receive a backscattered optical signal from the optical fiber under test and send the backscattered optical signal to the demultiplexer;
the demultiplexer is configured to divide the backscattered optical signal from the coupler into n optical signals according to wavelengths; and
the correlator is configured to perform, according to the correlation code pattern sequence from the code pattern generator, correlation processing on the n optical signals output by the demultiplexer and output a correlation optical time-domain reflectometry signal;
wherein the correlation code pattern sequence received by each modulator is a noncomplementary code;
wherein the detection apparatus further comprises a complementary light source configured to transmit a complementary optical signal; and
wherein the multiplexer combines the complementary optical signal with the n pulse optical signals transmitted by the n modulators and output a detection optical signal of constant power.
2. An optical time-domain reflectometry signal detection method, comprising:
modulating, under control of a correlation code pattern sequence, n detection optical signals transmitted by detection light sources of different wavelengths into n pulse optical signals, wherein n is a natural number greater than or equal to 2;
combining the n pulse optical signals and outputting a detection optical signal to an optical fiber under test;
receiving a backscattered optical signal from the optical fiber under test and dividing the backscattered optical signal into n optical signals according to wavelengths; and
performing correlation processing on the n optical signals according to the correlation code pattern sequence and outputting a correlation optical time-domain reflectometry signals
wherein the correlation code pattern sequence used for modulating every detection optical signal is a non-complementary code, and the combining the n pulse optical signals comprises:
combining the n pulse optical signals with a complementary optical signal transmitted by a complementary light source to obtain a detection optical signal having constant power.