金属微纳结构中的光热效应及其相关应用

发布时间：2018-02-23 16:37

本文关键词： 表面等离激元金属纳米结构光热效应微纳制备工艺激光光致前向转移光热调制器件　出处：《浙江大学》2016年博士论文　论文类型：学位论文

【摘要】：表面等离激元(SPP)由于具有近场光学增强与亚波长局域的特点,在光电集成、生物医疗、信息存储、超高分辨率成像等领域具有巨大的应用前景。光照射在金属纳米结构上,会激发表面局域增强的SPP光场。由于金属固有的对于光场的损耗性质,光能在金属纳米结构表面会转化热能,产生强烈的光热效应。金属纳米结构中的光热效应具有众多应用,本论文主要讨论了基于该光热效应实现金属纳米颗粒形变/转移及光热硅光调制器件的应用。本论文简要介绍了对于金属纳米结构中光热效应的理论基础,包括对入射光的散射/吸收、光热效应以及热传导过程。基于这些理论,可采用基于有限元方法的数值计算软件进行金属纳米结构在光的激发下产生光热效应过程的仿真,有助于对纳米结构进行设计优化及对实验现象进行理论解释。微纳制备工艺是纳米光子学领域的重要部分。通过理论和仿真设计的结构需要通过实际的制备工艺变成现实。本论文简要讨论了人工超材料光吸收器与基于光热效应的光热硅光开关制备过程,采用的工艺主要包括电子束曝光、电子束/热蒸发沉积、感应耦合等离子刻蚀等。同时介绍了相应的用于对纳米结构进行光学性能表征的实验系统。激光光致前向转移(LIFT)是基于金属中的光热效应实现金属纳米结构转移/制备的方法。人工超材料光吸收器对于特定波长入射光具有接近100%的吸收率,进而在结构中产生强烈的光热效应。利用这种高效光热效应,可进一步改进LIFT,大大降低对光源的需求,仅使用低工作功率(能量密度35 mJ/cm2)的纳秒激光即可实现单次照射实现大量的纳米颗粒转移。相北于化学生长方法,转移的金属纳米颗粒为单晶结构,表面没有化学残留。利用硅波导中的光热非线性效应可实现光热调制器件。将金属-介质层-金属结构的光吸收器集成到马赫·曾德尔干涉器上,利用光吸收器受到泵浦光激发产生的高效光热效应,对硅波导加热。通过改变泵浦光功率可实现器件输出信号光功率的调制,相比于传统光热调制器件,该方式实现了全光无接触式调制,无需制备额外的电接触,使得器件集成度更高(30μm×60 μm)。总而言之,本论文讨论了金属纳米结构中光热效应的理论研究与实验研究方法,提出了两种基于该光热效应的应用,有望应用于纳米结构制备及光电互联集成电路领域中。
[Abstract]:Due to the characteristics of near-field optical enhancement and sub-wavelength localization, SPPs have great application prospects in the fields of optoelectronic integration, biomedicine, information storage, ultra-high resolution imaging and so on. Because of the inherent loss of light field of metal, light energy can convert heat energy on the surface of metal nanostructure and produce strong photothermal effect. The photothermal effect of metal nanostructure has many applications. This paper mainly discusses the application of the photothermal effect to the deformation / transfer of metal nanoparticles and the photothermal silicon-photomodulation device, and briefly introduces the theoretical basis of photothermal effect in metal nanostructures. Based on these theories, the numerical calculation software based on finite element method can be used to simulate the photothermal effect of metal nanostructures excited by light. It is helpful to optimize the design of nanostructures and explain the experimental phenomena theoretically. The preparation process is an important part in the field of nano-photonics. The structures designed by theory and simulation need to be prepared by practical technology. In this paper, the fabrication process of artificial supermaterial optical absorber and photothermal silicon optical switch based on photothermal effect is briefly discussed. The processes used include electron beam exposure, electron beam / thermal evaporation deposition, Inductively coupled plasma etching and so on. At the same time, the corresponding experimental system used to characterize the optical properties of nanostructures is introduced. The laser photoinduced forward transfer (LIFT) is based on the photothermal effect in metal to realize the transfer of metal nanostructures. Artificial supermaterial absorbers have absorptivity of close to 100% for incident light at specific wavelengths, By using this kind of high efficiency photothermal effect, LIFT can be further improved, and the demand for light source can be greatly reduced. The nanosecond laser with a low working power (energy density of 35mJ / cm ~ 2) can realize a large amount of nanocrystalline particle transfer by single irradiation. There is no chemical residue on the surface. The photothermal modulation device can be realized by using the photothermal nonlinear effect in the silicon waveguide. The optical absorber with metal-dielectric layer metal structure is integrated into the Mach Zehnder interferometer. The silicon waveguide is heated by the high efficiency photothermal effect of the optical absorber excited by the pump light. The modulation of the output signal optical power of the device can be realized by changing the pump light power, compared with the traditional photothermal modulation device. This method realizes all-optical contactless modulation without additional electrical contact, which makes the device more integrated by 30 渭 m 脳 60 渭 m. In a word, the theoretical and experimental research methods of photothermal effect in metal nanostructures are discussed in this paper. Two applications based on the photothermal effect are proposed, which are expected to be used in nanostructure fabrication and optoelectronic interconnection integrated circuits.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TB383.1;TG111

【相似文献】