Programmable Photonic Circuit for Optical Logic Operations and 2-Bit Decoding

Abstract

We present a programmable silicon photonic circuit composed of cascaded multiport directional couplers interleaved with thermo-optic phase shifters. The device forms a reconfigurable interferometric network capable of realizing arbitrary $N \times N$ unitary transformations. By tuning the phase shifters, the same circuit can be configured to perform both optical logic gates and 2-bit decoding functions. Optimal phase settings are determined through Bayesian optimization. The circuit maintains stable operation across multiple wavelengths with 50 GHz spacing, suggesting potential for wavelength-parallel optical processing. These results highlight a pathway toward programmable and integrated photonic circuits.