An ultra-compact plasmonic unidirectional wavelength multiplexer/demultiplexer based on slot cavities is proposed and numerically simulated. The structure consists of slot cavities which are etched on either sides of a metal–insulator–metal (MIM) bus waveguide. The cavities capture surface plasmon polariton (SPP) waves at their resonant wavelengths and unidirectionally couples them to the drop waveguide etched parallel to the bus. The structure basically relies on resonance and interference of SPP waves and its functioning is validated through finite element method (FEM) simulations. The simulation results show that the proposed structure functions as expected with a full width at half maximum (FWHM) bandwidth of less than 50 nm, extinction ratio (ER) more than 10 dB, and crosstalk (CT) of less than − 10 dB for the designed wavelengths. The proposed structure holds lot of potential to enhance the miniaturization of ultra-compact integrated photonic circuits for optical signal processing and other related applications.

提出了一种基于槽腔的超小型等离子体单向波长复用器/解复用器并进行了数值模拟。该结构由蚀刻在金属-绝缘体-金属 (MIM) 总线波导两侧的槽腔组成。腔体在其谐振波长处捕获表面等离子体激元 (SPP) 波，并将它们单向耦合到平行于总线蚀刻的液滴波导。该结构主要依赖于 SPP 波的共振和干涉，其功能通过有限元法 (FEM) 模拟得到验证。仿真结果表明，所提出的结构按预期运行，半高全宽 (FWHM) 带宽小于 50 nm，消光比 (ER) 大于 10 dB，串扰 (CT) 小于 − 10 dB设计的波长。