Equivalent circuit model of semiconductor laser for high frequency FMCW LiDAR

Frequency modulated continuous wave (FMCW) light detection and ranging (LiDAR) can transmit and receive high frequency signals, up to 10G~100GHz, and can achieve micron-level high precision measurement and three-dimensional imaging of objects. If the frequency sweep of FMCW LiDAR is linearized, it can be extracted by Fourier transform, but most existing lasers do not have ideal linearity. In this paper, an iterative learning method of frequency sweep compensation is used to improve the linearity of frequency sweep. The semiconductor laser is one of the core components in the control system to improve the linearity of frequency sweep. Its performance determines the signal frequency and measurement accuracy of FMCW LiDAR. In this paper, the vertical cavity surface emitting laser (VCSEL) as an example, the equivalent circuit model of VCSEL is established by rate equation. An experimental platform is built to simulate the equivalent circuit model of the parasitic network, calculate and analyze each parameter, and verify the accuracy of the parameters of the equivalent circuit model and the parameter extraction method.