Ultra-broadband multi-character logic gates integrated by inverse designed logic units

Abstract

We propose a method to design multi-character logic gates, where the method of moving asymptotes (MMA) is used to design logic device unit structures, and then multi-character logic gates are constructed by integrating these basic logic units. With this approach, we successfully designed three-character AND and OR gates with dimensions of 2 μm × 3 μm, as well as four-character AND and OR gates with dimensions of 2 μm × 4 μm. The results show that the maximal contrast ratio of the three-character AND gate is 19.411 at wavelengths from 950 nm to 1600 nm, and the three-character OR gate achieves a maximal contrast ratio of 12.551 at wavelengths from 1200 nm to 1600 nm. For the four-character AND gate, the maximal contrast ratio is 9.269 at wavelengths from 950 nm to 1550 nm, while the four-character OR gate reaches a maximal contrast ratio of 17.754 at wavelengths from 1000 nm to 1600 nm. Compared to traditional binary logic gates, our multi-character logic gates achieve logical states directly without needing control ports, reducing design complexity and enhancing performance. These innovative logic gates have broad application prospects in future digital system designs.