Analysis Of Electromagnetically-inducedtransparency-like Effect Devices Based On Surface Plasmon Polaritons

Surface plasmon polaritons(SPP)are a special form of electromagnetic field formed by the oscillation of collective charge that is transmitted at the interface between metal and medium.It can realize the control of the light field in the sub-wavelength range and the local enhancement effect,break through the diffraction limit.Electromagnetically induced Transparency(EIT)effect is a quantum interference effect produced when the atomic layer interacts with the external light field,and can produce slow light effects and nonlinear effects.The micro-nano structure based on SPP realizes the EIT-like effect also known as Plasmon Induced Transparency(PIT).Based on the SPP metal-insulator-metal(MIM)structure,this paper carried out the following research work:1.Wavelength division multiplexer,which can make waves in the communication band 1310 nm,1490nm and 1550 nm wavelength output independently from the three output ends to achieve the purpose of demultiplexing.2.The double-disc coupling structure obtains the relationship between the resonant wavelength,coupling distance and refractive index,and achieves a good PIT effect.3.The T-shaped structure achieves a good PIT effect in one or two of the bands under the three-wavelength resonance condition,which provides a reference for the independent regulation of PIT in multiple bands.4.Multi-layer rectangular strip structure,which does not change the geometric size but changes the position of the PIT window by adjusting the refractive index,provides a certain reference for the controllable PIT device.5.The asymmetric cross structure introduces the concepts of horizontal asymmetry and vertical asymmetry,obtains the relationship between the resonance wavelength and the asymmetry under several degrees of asymmetry,and discusses the feasibility of implementing independently adjustable three-band PIT.