Suppression of the lock-in effect due to a MIOC frequency response in a fibre optic Sagnac interferometer

The sensor has a fiberoptic Sagnac interferometer (1) comprising a photodetector device (5), and an evaluation circuit (9) comprising a multifunctional integrated optical chip (MIOC) (11) with MIOC transfer function. The chip is arranged upstream of a digital filter (53), where filter-transfer function corresponds MIOC function. The interferometer has a setting unit to adjust coefficients of the filter function and a coefficient calculation unit to provide the coefficients to the setting unit, where the coefficients are computable by the calculation unit based on output signals of the chip. An independent claim is also included for a method for controlling a turning rate sensor.