An ultra-compact all-optical half-adder operating at 1550 nm on silicon-on-insulator is realized by a modular-inverse-design method which deconstruct the design of optical units with complicated functions to several devices with basic functions. The half adder is composed of five modules: two beam splitters, one hub, one XOR gate and one AND gate, all of which are designed by the same multi-objective particle swarm optimized method and have the equal area of 2 μm × 2 μm. The system is studied numerically by the Finite Difference Time Domain method. Remarkable contrast ratios of 12.0 dB and 8.45 dB are obtained for AND gate and XOR gate, respectively. The whole half-adder possesses an ultra-small area smaller than 10 μm × 5 μm, which results in a short respond time less than 0.7 ps and high respond speed beyond 1.4 THz. The contrast ratio between two output logic states “1” and “0” is around 7 dB and 15 dB for SUM and CARRY, respectively. The half-adder designed by modular-inverse-design method possess advantages such as tiny size, fast respond and high diversity, which indicates that our method has great potential as a universal method for the design of complicated integrated devices.

通过模块化逆设计方法，可将具有复杂功能的光学单元的设计分解为具有基本功能的多个器件，从而实现了在绝缘体上硅上以1550 nm工作的超紧凑全光学半加法器。半加法器由五个模块组成：两个分束器，一个集线器，一个XOR门和一个AND门，所有这些模块均通过相同的多目标粒子群优化方法设计，并具有2μm×2μm的相等面积。通过有限差分时域方法对系统进行了数值研究。与门和异或门的对比度分别为12.0 dB和8.45 dB。整个半加法器具有小于10μm×5μm的超小面积，这导致响应时间短于0.7 ps，响应速度超过1.4 THz。对于SUM和CARRY，两个输出逻辑状态“ 1”和“ 0”之间的对比度分别约为7 dB和15 dB。通过模块化逆设计方法设计的半加器具有体积小，响应速度快，多样性高等优点，这表明我们的方法作为设计复杂集成器件的通用方法具有很大的潜力。