In this study, a paradigm for modulating the light emission performance of photonic-crystal surface-emitting laser (PCSEL) via GaN high electron mobility transistor (HEMT) driving circuit is proposed for the first time. For light detection and ranging (LiDAR) system, a faster pulse repetition frequency with shorter pulse width can provide not only high resolution but also sufficiently precise range resolution. Hereupon, comprehensive analyses for such an integrated system are conducted with not only electro-optical responses but also the corresponding optical behaviors. The relevant electrical characteristics of the employed GaN HEMT are examined at first. Next, the integrated system on a matrix board with its corresponding circuit topology is discussed, illustrating the relevant operating principles. Thereby, sufficient systematical scrutinization for relevant light emissions is performed for both photodiode responses and the optical behaviors under different conditions, paving a holistic panorama for the LiDAR system. Thus, prospects for the next generation LiDAR system in high-power and high-speed operation can be expected.