面向下一代光通信的VCSEL激光器仿真模型

Vertical Cavity Surface Emitting Laser Simulation Model for Next Generation Optical Communication

研究光纤通信传输系统中VCSEL激光器仿真问题，建立能准确反映VC—SEL激光器特性的数学模型，确定模型参数并对L—I和S21两种特性曲线进行仿真分析．对于L—I曲线仿真，考虑到VCSEL的L—I模型存在对转换效率、经验热偏置电流及温度的近似处理误差，结合速率方程对L—I模型进行改进，以驱动电流、输出光功率的计算值与实测值的残差平方和最小为目标函数，建立双目标优化模型，运用遗传算法求解出改进后的L—I模型的参数方程．对于S21曲线仿真，在改进后L—I模型的基础上，将小信号加载到VCSEL，得到小信号输出频率的幅值响应．然后以驱动电流、光功率、小信号幅值响应的计算值与实测值的残差平方和最小为目标函数，建立多目标优化模型．运用遗传算法求解出带宽模型的最优参数，并仿真出不同温度和不同偏置电流下的带宽响应曲线，其中，20℃下7．5mA的仿真曲线与实测数对比的绝对误差和为25．36dB．

In this work, we study the simulation of Vertical Cavity Surface Emitting Laser （VCSEL） lasers in optical fiber communication transmission systems, the L-I and $21 were proposed to evaluate the characteristics of the VCSEL laser by establishing a mathematical model. For the simulation of the L-I curve, considering that the VCSEL＇s L-I model has an approximate processing error of conversion efficiency, empirical thermal bias current and temperature, this paper combines the rate equation to improve the L-I model. The multi- objective optimization model is established with the objective function as the minimum sum of the residuals of calculated and actual data of the drive current, optical power, and small- signal amplitude response Finally. Genetic algorithm is used to solve the parameter equation of the improved L-I model. For the $21 curve simulation, first, based on the modified L-I model, a small signal is loaded into the VCSEL to obtain the amplitude response of the small signal output frequency. Secondly, a multi-objective optimization model is established based on objective function that minimizes the sum of the residuals of calculated and actual data of the drive current, optical power and small signal amplitude response. Thirdly, the genetic algorithm is used to solve the optimal parameters of the bandwidth model, and simulate the bandwidth response curves at different temperatures and different bias currents. The absolute error sum of the simulated curve at 7.5 mA and the measured value at 20 ℃ is 25.36 db.