The invention discloses a distributed
fiber sound wave detection apparatus and method based on wave beam formation. The apparatus comprises a
light source, a 1*2 coupler, a control and
signal processing unit, an
arbitrary waveform generator, a double-channel parallel Mach-Zehnder electro-
optical modulator, a reference arm
fiber, an
erbium doped
fiber amplifier, an
optical filter, an annular device, a front-end reflector, a reference length fiber, a rear-end reflector, a sense fiber, a 90-degree optical mixer, and a balance
detector. The method includes the steps: injecting
signal light into the sense fiber, the
signal light being modulated to be light pulses with a
fixed frequency on a lower side and a sweep frequency on an upper side; mixing the returned
signal light carrying light phase information and light
frequency spectrum information of detecting points with local reference light; demodulating the light phase information and the light
frequency spectrum information, and obtaining the frequency, amplitude and phase information of sound
waves in the detecting points in the sense fiber; and finally calculating the position, intensity and frequency information of
sound sources. The sensing function and the
transmission function of a fiber are combined into one function. Therefore, the distributed fiber
sound wave detection apparatus and method have the advantages that the detecting point scale is hundred times higher than that of the prior art.