【作者】 闫鹏；

【导师】 费广涛；

【作者基本信息】 中国科学技术大学 ， 凝聚态物理， 2013， 博士

【摘要】 光子晶体是一种介电常数(或折射率)在空间周期变化的介电结构,在光子晶体中引入缺陷可以在光子晶体的截止带中出现缺陷峰。光子晶体以及存在缺陷的光子晶体在很多领域有应用前景。本文瞄准现有的氧化铝类光子晶体中存在的截止带带边不陡峭的问题、引入缺陷以及实际应用等方面开展工作。论文的主要研究内容如下：1、采用电流控制模式制备了氧化铝薄膜类光子晶体,有效克服了电压控制模式存在的孔道生长速度不均匀问题。考察了电流控制模式下周期时间、电流数值、占空比、温度和电解液组分等对氧化铝薄膜光学性能的影响。通过选择电流信号的周期时间,我们成功地制备了窄带隙(禁带半峰宽小于20nm)氧化铝薄膜。2、制备了具有缺陷峰的氧化铝薄膜,考察了缺陷引入电压的波形、大小、作用时间、位置和电解液浓度等对缺陷峰的影响。缺陷的位置和物理厚度对缺陷峰透过率的影响最大。3、以窄带隙氧化铝薄膜作为液体传感材料,研究了光子带隙位置(或透过率)与液体折射率之间相互关系。孔道表面的化学修饰能够使光子带隙发生移动,这为后续的探测奠定了基础。4、以油脂作为掩膜,在氧化铝薄膜局部引入缺陷,并以此薄膜为基础,提出了一种以红外线为工作波段的光学防伪技术。更多还原

【Abstract】 Photonic crystal is a kind of periodic structures containing ordered arrays with high and low dielectric constant components. Defect peaks will appear in the photonic band gaps (PBGs), if defects are introduced into photonic crystals. Photonic crystals with or without defects have application prospects in many filelds. The paper aims at solving slant band edge of PBGs, introducing defects and exploring practical use. The main content is as follows:1) A current controlled method was developed to fabricate porous anodic alumina (PAA) films, overcomeing the uneven pore growth in the voltage control mode. The periodic time, the current value, the duty ratio, the temperature and constituents of the electrolyte were investigated in the current control mode to examine their impacts on the optical property of PAA films. By selecting the proper periodic time, we successfully prepared the PAA films with narrow band gaps, of which half-peak width was less than20nrn.2) We have manufactured the PAA films with defects and analyzed the effects of various factors on the defect modes, including defect-introducing voltage waveform, voltage value, voltage duration, voltage sequence and electrolyte concentration. The position and physical thickness of defects played a leading role in determining the transmittance of the defect peak.3) Using PAA films with narrow band gaps as a sensing element for liquids, we studied the relationship between the PBG position or transmittance of PAA films and the liquid refractive index. The chemical modification on the pore surface could shift the position of PBG, which lay the foundation for selective recognition.4) Using the grease as a mask, we created defects in the selected sections of the PAA films. On the basis of this type of PAA films, we proposed an anti-counterfeiting technique working in infrared region.更多还原