Noise analysis of an electro-optic sensor system

This paper describes the noise analysis of an electro-optic (EO) sensor system based on experimental and simulation results. We developed a polarization simulator of the EO sensor system using the Jones vector and matrix. The polarization simulator included not only the laser intensity noise but also the laser polarization noise. The polarization noise was converted into an intensity noise due to the polarization noise using a polarizer after the laser source. We proposed a method to adjust differential balance using phasor diagram. The method is used for analysis of the noise characteristics. We expected that the existence of the laser polarization noise can be demonstrated by our experimental setup with and without the polarizer after the laser source. The noise characteristics of experimental results more than 4 kHz agreed with the simulation results under considering the effect of a receiver noise. However, the noise characteristics less than 4 kHz did not agree with simulation results. It was found that the noise characteristics less than 4 kHz are caused by the light intensity unbalance between p- and s- polarized light in our system.