Tunable optical buffer based on VO2/Si hybrid waveguide by optically induced phase transition

A tunable optical buffer composed of a side-coupled racetrack microring resonator (RMRR) sequence and phase change material vanadium dioxide (VO2) films has been designed and simulated with pass-through and drop functions. By optically induced phase transition of VO2, the number of coupled RMRRs is dynamically controlled to realize the required delay time and the ultra-fast response. Simulation results show that the buffer with 12 RMRRs achieves a tunable delay of up to 309.6 ps, a working bandwidth of 306 GHz, and a super-fast response of 0.62 ps. The delay loss and power consumption are 0.012 dB/ps and 0.194 mW/ps, respectively. These findings suggest a new approach to realizing tunable delay in all-optical networks.