The invention discloses an
optical fiber vibration sensing system of a single
light source pulse and a sensing method of the
optical fiber vibration sensing system of the single
light source pulse. Under the control of FPGA, a code is formed by an optical pulse, coded pulsed light is formed through a coupler, a sensing
optical fiber is injected through an optical
fiber circulator, interference is generated by
backward propagation scattered light generated in the process of the propagation of the sensing optical
fiber, the interference enters into the coupler through the optical
fiber circulator to be interfered with local oscillating light, and beat frequency signals are generated; the beat frequency signals are converted into electrical signals by a photoelectric
detector, difference frequency components are filtered through a band-pass filter circuit, the reduction of beat frequency is achieved through a
frequency mixer, at last the signals are collected and amplified by a collection card, in an upper computer, the respective
amplitude modulation and
demodulation of each control frequency are achieved, and decoding and location
processing are carried out. The optical fiber
vibration sensing system of the single
light source pulse has the advantages, peculiar to a distributed optical fiber detecting and
monitoring system, of being distributed and subject to small external disturbance such as
electromagnetism, the installation is convenient, and various vibration detecting and monitoring application, especially for long distance pipeline monitoring and
perimeter security, can be met well.