Electro-optical transient response study of pulsed VCSEL arrays

Abstract

Vertical cavity surface emitting laser (VCSEL) array is the important laser source in LiDAR ranging systems (LiDAR). The VCSEL array have important effects on the electro-optical transient response characteristics and power density for time-of-flight ToF ranging technology. In this study, by using the carrier-photon coupling equation of semiconductor lasers, we established a Simulink model of the rate equation of pulsed VCSEL arrays, an equivalent circuit model and a heat dissipation model of VCSELs. We analyzed the factors affecting the electro-optical transient response of pulsed VCSEL arrays theoretically. Then we verified the result experimentally. In this paper, the effects of array size and spurious parameters on the electro-optical delay time and optical pulse rise time of VCSEL arrays are discussed.Both simulation and experimental results show that the rise time of the VCSEL array decreases and then increases as the size of the array increases in the narrow pulse driving circuit. This provides a light source optimization scheme for the application of VCSEL arrays in LiDAR ranging systems (LiDAR). It also provides a theoretical basis for the in-depth study of VCSEL arrays under pulse driving.