基于T型腔结构的表面等离子体波导滤波器

摘要

Optical fields can be bound at sub-wavelength level by surface plasma polaritons (SPPs) and dif⁃fraction limit can be broken through. SPP is regarded as one of the most hopeful carrier to implement integrated optical devices in nanometer level. A surface plasma waveguide filter with T-shape cavity structure is designed. And its filtering characteristics are analyzed by finite difference time domain (FDTD) method. The results show that the center wavelength of transmission spectrum can be changed by the changing of length and width of T-shape cavity. Q values of cavities can be adjusted by changing the distances between cavities and coupling waveguide.%　　表面等离子体激元（surface plasmon polaritons, SPPs）能将光场束缚在亚波长量级，可以突破衍射极限，被认为是有希望实现纳米集成光学器件的载体之一。设计了一种T型腔结构的表面等离子体波导滤波器，并且利用时域有限差分（FDTD）法对其滤波特性进行了分析。结果表明，改变T型腔的长度和宽度可以改变透射谱的中心波长，而改变腔与耦合波导之间的间距，则可以调节腔的Q值。