利用电子束直写系统和反应离子束刻蚀的方法制作了周期性排列H-形空气槽.样品的参量：金膜的厚度为120 nm,石英基底的厚度0.8 mm(其中有5 nm厚的铬层),样品是由30×30个单个H-形周期排列形成的,总体尺寸为40×40 μm2.每个H-形之间的周期为1.1 μm,H-形的臂长均为500 nm,空气槽的宽度为120 nm.然后用实验的方法测量了在近红外波段的透过曲线,在近红外波段1.6 μm处的透过率约为16.3%,用传输矩阵的方法对H-形空气槽结构进行了理论模拟,实验与理论模拟结果吻合较好.随后研究了当入射光的偏振方向与H-形结构的长轴之间的夹角分别为0°、30°、45°、60°和90°时透过曲线的变化情况.通过实验和理论表明,表面等离子体在这种特殊的结构中仍然存在,并且在光的增强透过起着决定性的作用.

An enhanced near infrared transmission through periodic H-shaped arrays in metallic thin films is presented.The sample is fabricated by electron beam lithography and reactive ion etching system.The 0.5-mm-thick quartz substrate is deposited with a 120-nm-thick Au film and a 5-nm-thick chromium adhesion layer.The overall size of the sample is about 40×40 μm2,which is composed of 30×30 periodic H-shaped arrays.The period of the H-shaped lattice is 1.1 μm.The arm length of H-shaped is 500 nm and the line width is 120 nm.A broad transmission band centered at about 1.6 μm is found and the transmission coefficient can be as high as about 16.3% for a line width of 120 nm.A simulation by using transfer matrix method (TMM) reproduces quite well the obtained transmission spectrum.Polarization measurements of H-shaped arrays are also demonstrated.The results prove the important role of localized surface plasmon (LSP) in enhanced transmission through the special structure.