Patent ID: 11467060

Abstract:
An optical pulse test apparatus according to the present disclosure includes a light generation unit configured to generate an optical pulse for generating backscattered light beams in an optical fiber under test and generate first light having an optical frequency for amplifying backscattered light in an LP11 mode out of the backscattered light beams in two LP modes through stimulated Brillouin scattering, and second light having an optical frequency for attenuating backscattered light in an LP01 mode out of the backscattered light beams in the two LP modes through stimulated Brillouin scattering, a mode demultiplexing unit configured to input the optical pulse, the first light, and the second light generated by the light generation unit into the optical fiber under test in the LP01 mode and separate, out of the backscattered light beams generated by the optical pulse, the backscattered light in the LP11 mode, a local oscillation light generation unit configured to generate local oscillation light by which the backscattered light separated by the mode demultiplexing unit is heterodyne-detected, a light reception unit configured to multiplex the backscattered light in the LP11 mode separated by the mode demultiplexing unit and the local oscillation light generated by the local oscillation light generation unit and photoelectrically convert the multiplexed light into an electrical signal, and an arithmetic processing unit configured to calculate a time-intensity distribution of the electrical signal obtained by the light reception unit photoelectrically converting the backscattered light in the LP11 mode.