基于双矩形腔边耦合波导的等离子体诱导透明效应

为了降低功耗、实现超快速响应,设计了一种基于双矩形腔边耦合等离子体波导系统,并研究了其等离子体诱导透明效应.采用光学Kerr效应超快调控石墨烯-Ag复合材料波导结构,实现1 ps量级的超快响应时间.动态调控等离子体波导的传输相移,当泵浦光强为5.83 MW/cm^2时,等离子体诱导透明系统能够实现透射光谱π相移,这是因为基于石墨烯-Ag复合材料结构等离子体波导具有大的等效光学Kerr非线性系数,表面等离子体激元局域光场和等离子体诱导透明效应慢光对光学Kerr效应产生了协同增强作用,大大降低了系统获得透射光谱π相移的泵浦光强.等离子体诱导透明效应透明窗口的可调谐带宽为40 nm,系统的群延时控制在0.15 ps到0.85 ps之间,并且光波通过间接耦合或者相位耦合机制实现了等离子体诱导透明效应相移倍增效应.耦合模式理论计算结果很好地吻合了时域有限差分法仿真模拟结果,研究结果对于低功耗、超快速非线性响应和紧凑型光子器件的设计和制作具有一定的参考意义.

Plasmon Induced Transparency Effect Based on Two Stub Cavities Side-coupled Waveguide

In order to reduce the power and realize ultrafast response time,a plasmonic waveguide system based on two stub cavities side-coupled is designed,and a plasmon induced transparency effect is investigated.The plasmonic waveguide based on graphene-Ag composite material structures is tuned by the optical Kerr effect.An ultrafast response time of the order of 1 ps is reached.With dynamically tuning the propagation phase of the plasmonic waveguide,π-phase shift of the transmission spectrum in the plasmon induced transparency system is achieved under excitation of a pump light with an intensity as low as 5.83 MW/cm^2.The pump light intensity is reduced by adopting graphene-Ag composite material structures.The reason is that the optical Kerr effect is enhanced by the local electromagnetic field of surface plasmon polaritons,the slow light of the plasmon induced transparency effect and the plasmonic waveguide based on graphene-Ag composite material structures with giant effective Kerr nonlinear coefficient.The tunable bandwidth of about 40 nm is obtained.The group delay is controlled between 0.15 ps and 0.85 ps.Moreover,for the indirect coupling between two stub cavities or the phase coupling scheme,the phase shift multiplication effect of the plasmon induced transparency effect is found.The theoretical results are in good agreement with finite difference time domain simulations.Research results are of reference significance in design and fabrication of nanoscale integration plasmonic photonic devices with low power consumption and ultrafast nonlinear responses.