Integrated system for optical fiber sensing and communication through sharing co-frequency resources

An integrated system for optical fiber sensing and communication through sharing co-frequency resources, characterized in that, a transmission optical signal and a sensing detection light are generated by the same laser, transmission performance and sensing performance of the system are changed by adjusting modulation power of a transmission signal, the transmission signal is obtained by using direct detection at far-end, a sensing signal is obtained by using heterodyne coherent detection at local-end, and a specific structure is:

• continuous light output from a continuous wave laser (1) is divided into two paths after passing through a 90:10 fiber coupler A(2), 90% of the continuous light of an upper branch is injected into a mach-zehnder modulator A(4) after being adjusted by a polarization controller A(3), the mach-zehnder modulator A(4) operates in a carrier suppression modulation mode, the mach-zehnder modulator A(4) is driven by a linear FM signal generated by an arbitrary waveform generator (5) to generate a linear FM optical sideband, and light output from the mach-zehnder modulator A(4) passes through an optical filter (7) after being amplified by an erbium-doped fiber amplifier A(6), to retain only +1-order or −1-order sidebands and remove all remaining optical signals;
• a linear FM optical carrier output by the optical filter (7) is injected into a mach-zehnder modulator B(9) after adjusting a polarization state by a polarization controller B(8), the mach-zehnder modulator B(9) is driven by a transmission signal generated from another port of the arbitrary waveform generator (5), an optical signal output from the mach-zehnder modulator B(9), after compensating for optical power loss by an erbium-doped fiber amplifier B(10), is injected into an optical fiber (12) via an optical fiber annular (11), and an optical signal output from a far end of the optical fiber (12) is converted into an electrical signal with a photodetector (13), and is subjected to digital signal processing after being acquired by a data acquisition device (14);
• scattered light generated in the optical fiber (12) is output via a third port of the annular (11), output continuous light is coupled with continuous light output from a 10% output arm of the fiber coupler A(2) by a fiber coupler B(15) with a splitting ratio of 1:1, the 10% output arm of the fiber coupler A(2) is used as local light, two output arms of the fiber coupler B(15) are injected into two input ends of a balance detector (16) respectively, to perform photoelectric conversion, and an electrical signal output from the balance detector (16) is subjected to post-processing after being acquired by a data acquisition card (17).