Relative intensity noise suppression of intensity modulator and semiconductor optical amplifier

The source of the high-precision fiber optic gyroscope is a high-power erbium-doped fiber source. As the power of the source increases, the relative intensity noise becomes the main noise. Of all the noise created by the source, the relative intensity noise always restricts the random walk coefficient of the fiber optic gyroscope. So, the method of the relative intensity noise suppression needs to be taken to improve the accuracy of the gyro. In this paper, there are three methods, that is the external modulation method of intensity modulator, the method of connecting light source and SOA, and the external modulation method of connecting light source, SOA and intensity modulator. The modulation signal of the intensity modulator is created by FPGA, and input to the modulation end through the closed-loop control. The suppression effect of is tested and the level of inhibition is compared.