Electrically non-volatile/volatile programmable optical matrix

Abstract High-speed and energy-efficient scalable photonic switches are essential for next-generation optical interconnects and computing. However, existing techniques suffer from random fabrication variations, complicated calibration mechanisms, and limited switching speeds, which collectively hinder large-scale integration and high-robustness systems. Here, we present a monolithic 4 × 4 programmable optical matrix based on microring resonators (MRRs) integrated on a thin-film lead zirconate titanate (PZT) platform. We achieve non-volatile resonance wavelength alignment with sub-50 pm precision in the tuning range exceeding a full free-spectral-range (FSR) for all MRRs. The PZT MRRs simultaneously exhibit ultrafast electro-optic switching with a rising/falling time of 45/37 ps, respectively, along with negligible DC (direct current) drift (< 0.04 nm). When configured as an optical switch, the present optical matrix achieves a minimum excess loss of ~ 0.75 dB and maximum crosstalk suppression of ~ 43.2 dB. The optical matrix can also be configured as a wavelength-selective switch (WSS) with a maximum extinction ratio of 39 dB and an optical transmitter enabling high bit rates of 40 Gbps per channel. Furthermore, a reconfigurable optical weight matrix for non-volatile in-memory multiply-accumulate (MAC) computations is also demonstrated, potentially achieving 96.98% accuracy for handwritten digit recognition. This work successfully paves a routine to simultaneously achieve non-volatile programmability and volatile ultrafast modulation, offering a scalable and energy-efficient option for photonic integrated systems demanded for various applications of communications, signal routing, computing, and beyond.