SYNCHRONOUS AND LINE-SHARED DEMODULATION SYSTEM AND SENSING SYSTEM FOR OPTICAL FIBER SENSING NETWORK INTEGRATION

摘要

A synchronous and line-shared demodulation system and sensing system for optical fiber sensing network integration. The demodulation system comprises a single longitudinal mode laser (1), a fiber amplifier (2), a first coupler (3), a second coupler (5), a fiber grating wavelength demodulation unit (6), a high-frequency photoelectric detector (7), a polarizer (4), a pulse modulator (9), a polarization scrambler (10), a dual-port fiber ASE amplifier (11), a first circulator (12), a second circulator (14), a phase-shifted grating filter (8), a signal amplifying and filtering unit (15) and a Brillouin electro-optical signal frequency analysis unit (16). The first circulator (12) has a second port connected to a first port of the second circulator (14), and a second port and a third port of the second circulator (14) are connected respectively to an input end of the phase-shifted grating filter (8) and an input end of the high-frequency photoelectric detector (7). An output end of the signal amplifying and filtering unit (15) is connected to the Brillouin electro-optical signal frequency analysis unit (16). Characteristics of the system include diversity of functions, a simplified system structure, high compatibility, the capability to form a demodulation network and perform real-time, line-shared and synchronous monitoring, etc.