Optimization of band gap of photonic crystals fabricated by holographic lithographyX.-L. Yang1, L.-Z. Cai1, Y.-R. Wang1, C.-S. Feng1, G.-Y. Dong1, X.-X. Shen1, X.-F. Meng1 and Y. Hu2
1 Department of Optics, Shandong University - Jinan, 250100, China
2 School of Computer Science and Technology, Shandong University - Jinan, 250100, China
received 10 October 2007; accepted in final form 31 October 2007; published January 2008
published online 22 November 2007
Generally the photonic band gap (PBG) is a multi-variable function of several parameters related to the shape and size of the dielectric columns of photonic crystals (PhCs), and a time-consuming step-by-step scanning process for each parameter has to be used to find their best combination yielding maximum PBG. In this letter, the widely used Nelder-Mead simplex algorithm is introduced to optimize these parameters simultaneously to find a larger PBG for a new kind of two-dimensional (2D) hexagonal GaAs-Air PhC. This structure can be conveniently produced by the single-exposure holographic lithography, and the specific holographic design is also systematically investigated. This study reveals that the band gaps of PhCs made by holographic lithography may be widened by introducing irregularity of the columns and lowering the symmetry of the structure.
42.40.Kw - Holographic interferometry; other holographic techniques.
42.70.Qs - Photonic bandgap materials.
41.20.Jb - Electromagnetic wave propagation; radiowave propagation.
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