提出了一种可工作于可见光波段的波长可调的超透镜。该超透镜由一层等离子体金属薄膜和两侧等厚介质薄膜的平面波导构成。通过分析介质薄膜对波导表面等离子体模式的调制作用，给出了超透镜的成像规律。结果表明，通过调节透镜介质薄膜的厚度可实现从365~515 nm、分辨率为λ/6、高能量透射率的亚波长成像。该三层膜超透镜结构简单，可有效地减小制备误差及表面粗糙度对成像的不利影响，降低了制造难度。此结构以其简单的结构、出色的成像性能在亚波长光刻、生物显微镜、高密度数据存储等方面具有潜在的应用价值。

A superlens which can work at visible wavelength and whose work wavelength can be manipulated is proposed. It consists of a plasmonic metal film layer and two dielectric film layers. The relationship between the dielectric layer and the surface plasmon waveguide mode is analyzed, and its sub-wavelength imaging law is given. The results show that a sub-wavelength image with high transmittance and resolution of λ/6 can be obtained in the range of 365~515 nm. The fabrication tolerance and surface roughness can be greatly reduced, ascribed to its quite simple structure. Its simple structure and excellent sub-wavelength imaging capability opens a door for potential applications, such as sub-wavelength lithography, bio-microscopy and high intensity storage.