1. Scanning near-field optical microscopy study of metallic square hole array nanostructures.
- Author
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Li, Jiang-Yan, Li, Zhi-Yuan, Yang, Hai-Fang, and Jin, Ai-Zi
- Subjects
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ION bombardment , *NEAR-field microscopy , *PHYSICS education , *OBSTRUCTIONS of lighting , *NANOSTRUCTURES , *NANOELECTROMECHANICAL systems - Abstract
We fabricate periodic arrays of simple-square and composite-square air hole nanostructures on a 120 nm thick Au film deposited on glass substrate by focused ion beam technology and study their optical properties by examining the optical near-field distribution via scanning near-field optical microscopy in the near-infrared region. The simple-square nanostructure only contains one square air hole in each unit cell, while the composite-square one contains the same size square air hole in the center and eight smaller square air holes in the periphery. The measured optical near-field patterns for the two nanostructures show very different distribution features. High intensity light spots locate within the central square air hole in the simple-square structure, while they sit at the peripheral smaller square air holes in the composite-square structure. Numerical simulations based on the plane-wave transfer-matrix method have been carried out to analyze the optical near-field patterns for the two metallic nanostructures and agree well with the experimental data. The results indicate that light interaction with metallic nanostructures is very sensitive to even a small change in the subtle geometrical feature. Meanwhile, by comparing near-field patterns with dielectric nanostructures theoretically, we also find that optical confinement is better for gold nanostructures than for dielectric nanostructures. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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