The possibility of recording weak seismic waves using fiber-optic accelerometers placed on the ice cover is considered. The results of experimental studies of a fiber-optic accelerometer with a threshold sensitivity 10<sup>-7</sup> m/s<sup>2</sup> are presented. This experiment was held in winter in the Amur Bay (Sea of Japan). The results of recording seismic signals propagating in the ice cover during the motion of objects on ice are presented. The results of recording weak seismic signals propagating in the ice cover during the operation of a low-frequency hydroacoustic emitter are presented. The obtained results prove the possibility of using the presented fiber-optic accelerometer for recording weak seismic waves propagating in the ice cover to solve seismic monitoring problems in the Arctic offshore.
To the present time photorefractive (PRC) crystals have found wide application at creation interferometers
devices. It is caused by presence in photorefractive environments of nonlinear optical effects. One of such effects is
the effect polarization self-modulation
One-fiber few-modes interferometers are used for creation of sensors of physical sizes, but there is a
problem of processing of their output signals. In this report, I review the method of processing of output signal with
the help of the effect polarization self-modulation in PRC for one-fiber few-mode interferometer (in which
propagate only 2 or 3 modes).
The submitted method in comparison with existing methods has the following advantages: the linear
transfer characteristic and signal is formed on the first harmonic. The installation is assembled, with which help the
idea of processing of an output registered signal in one-fiber few-modes interferometer was embodied.
Besides as addition, the application photorefractive crystals opens an opportunity of giving to measuring
system an ability to adapt under at slow changes of an environment, for example, slow temperature changes.