A method of minimizing the frequency stabilization sensitivity for four frequency differential laser gyro

The frequency stabilization error is an important error source to limit the precision of four frequency differential ring laser gyro (DILAG) in navigation application. Different from the traditional technology mainly related to frequency stabilization circuits design, this paper introduces a new method to solve the problem. The method can essentially minimize the frequency stabilization sensitivity of DILAG, by applying an outer longitudinal magnetic field to the gain region of DILAG. Through adjusting the value of magnetic field to make the frequency splitting equal to the Faraday splitting, the minimum frequency stabilization sensitivity of DILAG will be available. The physics mechanism and mathematic model of this method are analyzed and set up. Concrete steps to realize the method are given in detail. Experimental results have verified its validity and it can decrease the startup drift. Hence, this new method can improve the performance of DILAG, which will be helpful to navigation application.