LASER INTERFERENCE HYDROPHONE Russian patent published in 2021 - IPC G01L23/06 

FIELD: geophysics.

SUBSTANCE: invention relates to geophysics and to measuring technology, and can be used for measuring micro-oscillations of underwater pressure and for studying the spatial and temporal structure of geophysical fields of infrasound and sound range. The claimed laser interference hydrophone is in the form of a hermetic housing comprising a recording system, an optical system based on a Michelson interferometer and a system for compensating external pressure. The optical system comprises a monochromatic radiation source, an optical ray divider dividing the beam of the radiation source into a reference and a measurement source. The reference beam passes through a fixed reflector in the form of two flat parallel mirrors mounted on piezoceramic bases at an angle of 90° to each other, and the measuring beam passes through the collecting lens and the movable reflector. After the passing of both rays along their trajectories, they are brought back together on an optical divisor, and the interference formed in the resulting beam enters, through the photodetector, a recording system capable of changing the length of the optical path. The external pressure compensation system comprises a compensation chamber provided with a valve, which chamber is formed by the end wall of the housing, which wall is provided with a detachable membrane and is provided with a partition parallel thereto. The movable reflector is in the form of a mirror which is immovably mounted on one end of the rod, the second end of which is connected to the centre of the membrane via a movable radial seal of the bulkhead opening.

EFFECT: technical result is increased range of working depths of the hydrophone to maximum depths, improved quality of the interference pattern due to the absence of a weakening of the measuring beam, which in turn increases sensitivity of the hydrophone, and also makes it possible to use it as a liquid as well as gas ballast.

1 cl, 1 dwg