Gyro is a high precision inertial sensor.The resonant optical gyroscope

as the second generation of gyro

has higher precision than interference optical gyro.Because the stability of the gyro resonance frequency greatly influences the precision of the resonant optical gyro

the frequency stability and tunable performance of the light source is very important.The common source which meets the requirement

usually has large size.It is not conducive to miniaturization and integration.A control scheme of a semiconductor laser based on external cavity semiconductor laser on the basis of detection principle of the resonant optical gyro is introduced.The testing of new light source is also analyzed and designed.A proposition of constant temperature and control of current is put forward on the basis of analyzing the modulating signal of the light source.The current characteristic of external cavity semiconductor laser and the signal of entering the valley of the resonant gyroscope are analyzed.