High-efficiency ultra-fast all-optical photonic crystal diode based on the lateral-coupled nonlinear elliptical defect

Abstract

An all-optical Fano-like diode featuring a nonlinear lateral elliptical micro-cavity and a reflecting column in the photonic crystal waveguide is proposed. The asymmetric micro-cavity is constructed by removing one rod and changing the shape of the lateral rod from a circle to an ellipse. A reflecting pillar is also introduced in the waveguide to construct a F-P cavity with the elliptical defect and enhance the asymmetric transmission for the incident light wave transmitting rightwards and leftwards, respectively. By designing the size of the ellipse and optimizing a reflecting rod at a suitable position, a maximum forward light transmittance of -1.13 dB and a minimum backward transmittance of -57.65 dB are achieved at the working wavelength of 1550.47 nm. The corresponding response time is about 10 ps when the intensity of pump light beam resonant at 637 nm is 3.97 W/μm2.