基于非线性光纤环镜的40Gb/s可重构光逻辑门

提出了一种新型的基于非线性光纤环镜(NOLM)的可重构全光逻辑门实现方案。传统的基于NOLM的全光逻辑利用自相位调制效应或交叉相位调制效应,透射传输函数重构的自由度低,可实现的逻辑门种类较少。该方案在传统的结构基础上,分析了NOLM中探测光的偏振态的演化,以及输入光偏振态和环内偏振控制器对NOLM的传输特性的影响。理论分析和数值仿真结果表明在考虑NOLM中的非线性偏振旋转效应的情况下,可以更加自由地构建不同透射传输函数,从而利用单一NOLM结构,仅通过调节偏振控制器,即能够可重构地实现绝大部分基础组合逻辑。实验中,完成了两路40Gb/s的数据信号之间的"非"、"与"、"或"、"或非"、"同或"、"异或"等各种基础组合逻辑,验证了方案的可行性。

40 Gb/s Reconfigurable All-Optical Logic Gate Based on Nonlinear Optical Loop Mirror

All-optical ultra-fast and reconfigurable logic gates have been implemented by exploiting simple and low-cost schemes based on nonlinear optical loop mirrors (NOLM). Conventional NOLM-based all-optical logic gates utilize the self-phase modulation effects or cross-phase modulation effects. Thus, types of logic gates that can be achieved are limited by the low degree of freedom in reconstruction of the transmission function. Here, an improved scheme of NOLM-based all-optical logic gate is proposed by exploiting the nonlinear polarization rotation in the NOLM. The evolution of the polarized state of light is analyzed as well as the effect of the polarization of the input light and the polarization controller in NOLM. Theoretical analysis and numerical simulation results show that all the basic logic gates can be realized using a single NOLM structure, only by adjusting the polarization controller. Because it is more free to rebuild the transmission function when the nonlinear polarization rotation effect is taken into account. We demonstrate the feasibility of the scheme experimentally by realizing all-optical logic gates of “NOT”, “AND”, “OR”, “NOR”, “XOR”, “NXOR” at 40 Gb/s operation.