Single-Monitor Calibration for Multiple Microring Synapses

Microrings hold significant applications in optical analog computing and can be arranged in an array to establish photonic weight banks for matrix–vector multiplication. However, microrings face challenges in precision and stability due to the sensitivity to internal thermal crosstalk and environmental disturbances; thus, massive monitors (usually bulky instruments) are needed to calibrate weights of massive microrings. Until now, multiple microring synapses had not been simultaneously calibrated with only one monitor. To address this issue, we propose a single-monitoring scheme to simultaneously calibrate multiple microring weights. In the experiment, we demonstrate the ability to simultaneously calibrate weights of 16 microrings with excellent immunity to environmental fluctuations and internal crosstalk. Furthermore, the scalability of this scheme offers a novel outlook for enhancing the precision of large-scale microring-based systems while simultaneously mitigating the equipment demands associated with calibration.