Compact and efficient PC-based directional coupler all-optical switch

Recently, the photonic crystal–based optical components and devices have attracted many researchers’ attention because of its nanoscale size which makes it suitable for the photonic integrated applications. Hence, the design of all-optical switch based on photonic crystal structure have been investigated in the past few decades to meet the requirement of ultracompact size with optimized performances such as fast response time, high extinction ratio with low insertion loss. Here, the design of directional coupler–based all-optical switch operating at the wavelength of 1550 nm is proposed with new design values. The resonant operating wavelength of the switch is identified with the help of finite element method. Then, the cross-state switching operation is analysed with the help of finite-difference time-domain method by applying a nonlinear optical Kerr effect switching mechanism. The important performance metrics of the proposed design such as insertion loss, extinction ratio, directivity and the response time are obtained as −0.008 , 26.98, 20.44 dB and 0.13ps, respectively. The total footprint of the proposed optical switch is approximately 128 µm2.