基于马赫-曾德尔干涉仪的全光逻辑异或门理论研究

Theoretical study of all optical XOR using Mach-Zehnder interferometer

基于半导体光放大器(SOA)和线性光放大器(LOA)构成的马赫曾德尔干涉仪(MZI),从速率方程出发,模拟了LOA的泵浦放大和增益箝制特性,建立了SOA MZI和LOA MZI结构全光异或门数值模型,通过控制探测光功率和偏置电流,实现了两路40Gbit/s信号的异或运算。并通过求解速率方程,对异或运算的结果进行了分析和比较;从器件结构上对2种异或门运算结果的差异给出了解释。结果表明:SOA和LOA中载流子恢复时间限制了信号处理速度;合理控制偏置电流和探测光功率可以提高信号处理能力;LOA具有增益箝制作用,对输入信号的扰动具有不敏感性;与SOA MZI异或门相比,LOA MZI异或门输出信号的消光比较高,功率较低;对于输出脉冲波形而言,LOA MZI异或门性能优于SOA MZI异或门。

Two kinds of Mach-Zehnder interferometers (MZI) were constructed by semiconductor optical amplifier (SOA) and linear optical amplifier (LOA), respectively. Based on rate equations, the pumping amplification and gain clamped behaviors of LOA are simulated. With the control of probe beam power and bias current, all-optical XOR functionality is simulated using integrated SOA-MZI and LOA-MZI numerical model at 40 Gbit/s. The performance of the XOR results is analyzed and compared by solving the rate equations numerically. The result differences of the XOR gates are explained from the structural properties. The theoretical results indicate that the high-speed operation is limited by the carrier recovery time in the SOA and LOA; the operation rate can be enhanced with appropriate bias current and probe beam power; LOA clamps the gain and improves tolerance against small signal distortion; the output signals of LOA-MZI have higher extinction ratio and lower power compared with SOA-MZI; LOA-MZI has better performance in output pulse shape than SOA-MZI.