Output characteristic of four-frequency Zeeman laser gyroscope with an alternating frequency bias

We have experimentally studied the output characteristic of a four-frequency Zeeman laser gyroscope (ZLG) on longitudinal modes with orthogonal circular polarisations having an alternating frequency bias and compared it with the output characteristic of a two-frequency ZLG. It is shown that by representing a four-frequency ZLG as a set of two-frequency ZLGs with orthogonal polarisations, the output characteristic of a four-frequency ZLG can be obtained through the arithmetic mean of the output characteristics of the same gyroscope. The experimental output characteristic of a four-frequency ZLG with an alternating bias in the form of a meander with a switching frequency of 1 kHz, as well as its combination with a low-frequency meander with a frequency of 1 Hz, is presented. The efficiency of using slow meander modulation for the linearization of the output characteristic of a four-frequency ZLG is demonstrated.