Optically Controllable Gray-Level Diffraction from a BCT Photonic Crystal Based on Azo Dye-Doped HPDLC

• 作者: Andy Ying-Guey Fuh Chung-Hung Liu Jui-Hsiang Liu Ming-Hsien Li Shing-Trong Wu
• 来源期刊: 光学与光子学期刊(英文)
• 学科: 医学
• 关键词: All Optically Control Gray-Level PHOTONIC Crystals HPDLC
• 年，卷（期）: 2014,（10）
• 页码范围: 288-295
• 页数: 8页
• 分类号: R73

摘要

We investigated optically controllable gray-level diffraction from a body-centered tetragonal photonic crystal that was based on an azo-dye-doped holographic polymer dispersed liquid crystal. The sample is fabricated by use of two-beam interference with multi-exposure. Bichromatic pumping beams at various intensities were used to pump the sample to change the concentration of the cis isomer and, in turn, modulate the effective index of the photonic crystals as well as their diffraction intensity. Three pumping processes were utilized to produce gray-level switching of diffractive light. This study demonstrates the optimum gray-level to be 15-level of up-step and down-step. The simulation of the diffraction intensity under bichromatic pumping sources was also studied.