A novel passive all-optical full subtractor device is realized using a two-dimensional (2-D) photonic crystal. The proposed structure is realized using the concept of beam interference in a sequence of T- and Y-shaped line-defective waveguide structures made of a linear material such as silicon with air as the background medium. The major advantage of this design approach is the avoidance of nonlinear materials and semiconductor optical amplifiers. In addition to the actual input ports, some reference input ports are also utilized to achieve the desired full subtractor functionality. The different input combinations to the full subtractor are given and optimized via several simulations. The full subtractor functionality is validated using the Opti-FDTD tool. The simulation results for the full subtractor are supported by the E-field distribution and power analysis at the output ports for different input logic values at a wavelength around 1550 nm. The proposed structure shows a fast response time of 0.16 ps, a bit rate of 6.25 Tbps, and a contrast ratio of 3.97 dB, and occupies an area of 465 µm².

一种新颖的无源全光全减法器器件是使用二维（2-D）光子晶体实现的。所提出的结构是利用光束干涉的概念实现的，在一系列由线性材料（例如硅）制成的T形和Y形线缺陷波导结构中，空气为背景。这种设计方法的主要优点是避免了非线性材料和半导体光放大器。除了实际的输入端口外，还使用一些参考输入端口来实现所需的全减法器功能。通过几个模拟给出并优化了全减法器的不同输入组合。完整的减法器功能已使用Opti-FDTD工具进行了验证。全减法器的仿真结果由Ë在对于不同的输入的逻辑值输出端口-field分布和功率分析在约1550nm的波长。所提出的结构显示出0.16 ps的快速响应时间，6.25 Tbps的比特率和3.97 dB的对比度，并且占据了465 µm ²的面积。