ROF系统中典型光电探测器转换效率的研究

Research on the conversion efficiency of typical photodetectors in ROF system

摘要:

随着光载无线通信系统（Radio over Fiber，ROF）的快速发展，光电转换效率已成为衡量其性能的重要因素。本文通过理论分析、仿真研究和系统实验探讨了影响光电转换效率的关键因素。首先，通过理论分析表明，当光斑形状与探测器光敏面匹配时，可实现最佳的光电转换效率；然后，通过ZEMAX仿真发现，在给定光源和传输距离的条件下，当光斑半径是探测器光敏面半径的1/2时，接收的光功率最大；继续改变激光发散角从3°增大至30°，光功率从3mW迅速下降至0.56mW、且光斑图像趋于饱和；此外，激光传输距离的增加也会导致光束束宽和发散程度增大，从而降低探测器的接收光功率。最后，搭建了一套小型ROF实验系统，通过CMOS相机光斑采集以及光功率探测实验验证了仿真结果的正确性。

Abstract:

With the rapid development of the Radio over Fiber (ROF) system, photoelectric conversion efficiency has become an important factor in evaluating its performance. This paper investigates the key factors affecting photoelectric conversion efficiency through theoretical analysis, simulation studies, and system experiments. First, theoretical analysis reveals that optimal photoelectric conversion efficiency is achieved when the beam spot shape aligns with the photosensitive surface of the photodetector. Then, using ZEMAX simulations, it is found that under given light source and transmission distance conditions, the received optical power is maximized when the beam spot radius is half the radius of the photodetector's photosensitive surface. Furthermore, as the laser divergence angle increases from 3° to 30°, the optical power rapidly decreases from 3mW to 0.56mW, and the spot image tends to be saturated. In addition, as the laser transmission distance increases, the beam width and divergence increase, reducing the detector's received optical power. Finally, a small-scale ROF experimental system is established, and the accuracy of the simulation results is verified through CMOS camera-based spot acquisition and optical power detection experiments.