The Spectral Response of the Dual Microdisk Resonator Based on BaTiO₃ Resistive Random Access Memory

With the resistive random access memory (ReRAM) devices based on the Al/BaTiO₃ (BTO)/ITO structure fabricated at hand, by cross-analyzing the resistive memory characteristics in terms of various barium titanate (BTO) film thicknesses, it is found that the device with 60 nm thick BTO can be switched more than 425 times, while the corresponding SET/RESET voltage, the on-off ratio, and the retention time are −0.69 V/0.475 V, 10², and more than 10⁴ seconds, respectively. Furthermore, the aforementioned ReRAM with a low switching voltage and low power consumption is further integrated with a waveguide resonator in the form of a dual microdisk aligned in a parallel fashion. As the separation gap between the two microdisks is fixed at 15 μm, the ReRAM-mediated dual disk resonator would render a 180° phase reversal between the spectral outputs of the through-port and drop-port. If the gap is shortened to 10 and 5 μm, the expected phase reversal could also be retrieved due to the selective combinations of different memory states associated with each of the two ReRAM microdisks as witnessed by a series of characterization measurements.