MZI-Based Optical Circuit for MIMO Signal Detector Immune to Fabrication Errors

This paper presents a design method for Mach-Zehnder interferometers (MZIs)-based optical circuits intended for MIMO signal detection that are robust against fabrication errors in MZIs. Typically, faulty MZIs can critically impair the functioning of optical circuits. Our primary objective is to devise a design strategy that ensures the reliability of optical circuits for MIMO linear detection even when faced with faulty MZIs. The cornerstone of our approach is the adjustment of parameters in functional MZIs by minimizing the receiver's mean squared error using a gradient descent method. Numerical experiments underscore that our method enables signal detectors, even with faulty MZIs, to approach the performance of an ideal, faultless MMSE MIMO detector.