A Photonic Crystal Functional Device Based On The Kerr Effect

Compared with electrons,photons have the advantage of fast transmission speed,low energy loss,high information capacity,strong anti-interference ability,and can transmit in free space.The photonic crystal is an artificial periodic dielectric structure characterized by the existence of the photonic band gap,and it is widely used in all-optical functional devices owing to its good light controlling ability.All-optical diodes have similar unidirectional transmission function as electronic diodes,but the transmission rate,signal-to-noise ratio,and anti-interference ability of optical diodes are much higher than those of the electric diodes.In the all-optical communication,a switch is inevitable.It needs to control the signal conduction and cut-off of each port,so a device that can control the free switching of multiple output ports is required to achieve this function,and the all-optical tunable beam splitter can satisfy this need.In this paper,two functional devices,photonic crystal all-optical diodes based on the Kerr effect and three-output-channel tunable photonic crystal beam splitter based on nonlinear resonators,which will have potential application in the future all-optical integration and all-optical communication,respectively.Based on the Kerr effect,we designed a photonic crystal all-optical diode with the side-coupled elliptical micro-cavity.The proposed device consists of a W1-typed waveguide,an asymmetric point defect,a side-coupled elliptical micro-cavity,and a reflective pillar.The pump light and signal light are input from the same direction along the W1 waveguide,and the one-way propagation is achieved by changing the pump light intensity.The working wavelength of the proposed structure is 1550.47 nm,and the working wavelength of pump light is 637.00 nm.The maximum forward transmittance of this structure is-1.13 dB,the lowest reverse cut-off transmittance is-57.65 dB,and the required response time is 10 ps.Based on the nonlinear resonators and self-collimation characteristics of the light beam,we designed an all-optical photonic crystal beam splitter.The proposed device consists of one input waveguide and three outout waveguides connected to different ring resonators.Three pump beams transmit through different resonators via the self-collimation effect,and eight output states are realized by altering the intensity of the pump light.The proposed device works at the wavelength of 1629.57 nm and the pump wavelength is located at 1240.00 nm.The transmittance contrast between the states "on" and "off" reached a maximum value of 124.0 and a minimum of 17.6.The minimal pump light intensity required to implement the performance is only 0.162 W/?m2,while the maximal value is about 0.497 W/?m2.