Proposal for a Kerr-Tunable All-Optical Switch Based on Photonic Crystal Ring Resonators

in this paper, a Kerr-tunable all-optical switch is presented which works in photonic crystal platform and implement octagonal-shape ring resonator(s) for enhancing the level of nonlinear light amplitude required for the device operation. Two switches are designed and compared; one based on a single (SR) and the other based on a double-vertically (DR) aligned ring resonators. Silicon (Si) nanocrystal is used as the driving material for the nonlinear parts. Since the transmission spectra of the DR switch has a higher Q-factor rather than SR and also since the optical power reads more nonlinear rods within the DR, thus the optical power required is much lower (at least 10 folds) than the SR switch. The required time for DR switch to change its state from on to off is computed to be less than 10ps, at λ0=1552nm. The minimum power required to turn DR switch state on/off is less than 6mW/µm2. Performance of the switch is simulated by means of finite difference time domain (FDTD) method, which confirmed the ultra-compact sized for the structure working with an ultrafast speed.