Calibration-free reconfigurable silicon optical signal processor

Reconfigurable silicon optical signal processors using interferometer meshes are essential in optical interconnection and optical computing systems. However, due to random phase errors in the tuning elements, most of the pervious demonstrations either require hundreds of self-configuration iterations or calibration of all the tuning elements. Here, we propose and demonstrate a calibration-free silicon optical signal processor based on 5$\times$ 5 interferometer mesh using low-phase-error Mach-Zehnder interferometer (MZI). The proposed processor can be tuned easily to achieve various functions, including multi-channel optical switch and matrix multiplications. Our work paves the way towards large-scale calibration-free silicon photonic MZI-based processors.