Figure 2: MRR non-volatile memory functionally.
From: Integrated photonics with programmable non-volatile memory

(a) The MRR transmission spectra at ON (blue) and OFF (red) states. Inset figure is microscopy picture of device. (b) The resonance wavelengths at ON and OFF states when the device is repeatedly programmed and erased for 30 sequential cycles. (c) The resonance wavelengths at ON and OFF states were unchanged within 20 hours.