FIELD: measurement technology. SUBSTANCE: given device incorporates radiation source, five dividers of optical power, three phase modulators, three fibre-optical coils, three polarizers and photodetector. Sensitivity axes of fibre- optical coils are reciprocally orthogonal. Count-down ratio of divider of optical power which input is connected to radiation source is 1: 2. Divider of optical power which input is connected to output of first divider has count-down ratio 1:1. Optical circuit of device provides for effective usage of optical power that leads to increased sensitivity of device. EFFECT: increased sensitivity of device. 4 dwg
