双光子吸收对光子晶体定向耦合全光开关的影响

Effect of two-photon Absorption on all-optical switch based on photonic crystal directional coupler

利用时域有限差分方法,在非线性条件下,考虑双光子吸收效应的同时,建立了分析2维光子晶体定向耦合波导光开关的模型。数值计算结果表明,对于长度较短的波导耦合器件,在强控制光和非线性条件下,双光子吸收效应会对波导的耦合作用产生一定的影响,从而改变入射光的透射特性,使光开关控制的动态过程发生变化。故而在设计全光开关器件时,对强控制光条件下的非线性双光子吸收效应有必要作为影响因素考虑进去。

An analytic approach to all-optical switch was present, and the two-photon absorption effect were taking into account to analyze all-optical switch, which is based on two-dimensional photonic crystal directional coupler, by means of the finitedifference time-domain method. The numerical study shows that, for short device and high intensity control beam, nonlinear twophoton absorption（TPA） can take effect on the process of coupling action in all-optical switch, and then change the transmission characteristics of input beam. Therefore, under realistic conditions, TPA should be considered in desgning all-optical switch devices based on photonic crystal directional coupler.