Calibration-free 6 × 6 Mach–Zehnder switch for Optical network-on-chip

We have proposed and implemented a calibration-free $2 \times 2$ Mach-Zehnder switch (MZS) and a calibration-free $6 \times 6$ MZS array, featuring an excess loss of $\sim 2.5$ dB and an extinction ratio $\gt$20 dB across the C-band without any calibration.