太赫兹波超材料激光诱导化学镀制备技术研究

发布时间：2018-11-25 17:39

【摘要】：超材料是由亚波长结构单元周期性排列组合成的人工复合材料。通过改变共振单元的结构形状或尺寸可以灵活地改变材料对电磁波的响应,实现如吸波器、滤波器、传感器和偏振器等各种功能器件。随着微加工技术的蓬勃发展,使太赫兹波段的超材料成为可能。太赫兹波超材料的制作通常采用传统光刻的方法,但是该方法流程复杂,而激光诱导化学镀作为一种新型加工工艺以其简便、灵活和低成本的优点逐渐受到研究者的青睐。本文主要研究了太赫兹波超材料的制备技术激光诱导化学镀。实现了双层金属结构的超材料制作,并分别制备了单层类电磁诱导透明谐振器和双层金属线栅偏振器。经太赫兹时域光谱系统(THz-TDS)测试证明该方法简便有效。本文主要研究工作如下:(1)研究了一种太赫兹波超材料的制备技术—激光诱导化学镀。首先利用激光曝光在涂覆有Ag NO3胶体的聚合物材料表面图形化沉积金属银,然后进行化学镀实现铜镀层的沉积。主要工作包括表面处理、激光直写和化学镀铜等工艺研究,重点介绍了激光直写参数对金属线的影响、自动对焦的实现以及双层金属结构超材料的实现。(2)利用时域有限差分法(FDTD)对由同心的大小圆环组合成的双圆环(DR)结构进行了仿真分析,并利用激光诱导化学镀技术在45μm聚酰亚胺(PI)薄膜上制备了DR样品。THz-TDS测试结果表明该DR结构具有类电磁诱导透明(EIT)效应。在0.42 THz附近出现了一个透明窗口,谐振峰的Q值为12,相比单独圆环提高了一个数量级。(3)设计并制备了双层金属线栅结构的太赫兹波偏振器,采用45μm的PI薄膜为基底,利用激光诱导化学镀技术在基底两面分别制作了金属线栅。利用FDTD对单双层线栅偏振性能进行了对比,并分析了基底厚度、金属厚度、基底损耗和两层线栅之间偏移量对双层线栅偏振器(BWGP)性能的影响。经THz-TDS测试,在0.2~1.6 THz范围内,BWGP的TM波透过率高达67%,消光比超过45 d B,明显高于单层线栅偏振器。
[Abstract]:Metamaterials are artificial composites composed of subwavelength structure units arranged periodically. By changing the structure shape or size of the resonance unit, the response of materials to electromagnetic waves can be changed flexibly, and various functional devices such as absorbers, filters, sensors and polarizers can be realized. With the rapid development of micro-fabrication technology, terahertz-band metamaterials become possible. Traditional lithography is usually used to fabricate terahertz wave supermaterials, but the process is complicated, and laser induced electroless plating (LECP) as a new processing technology has been favored by researchers for its advantages of simplicity, flexibility and low cost. The preparation technology of terahertz wave supermaterial was studied in this paper. The supermaterial fabrication of double metal structure is realized, and monolayer electromagnetically induced transparent resonators and double metal wire gate polarizers are fabricated respectively. The method is proved to be simple and effective by terahertz time domain spectroscopy (THz-TDS). The main work of this paper is as follows: (1) the preparation technology of terahertz wave supermaterial, laser induced electroless plating, has been studied. Firstly, silver was graphically deposited on the surface of polymer coated with Ag NO3 colloid by laser exposure, and then electroless plating was carried out to achieve the deposition of copper coating. The main work includes surface treatment, laser direct writing and electroless copper plating. The influence of laser direct writing parameters on metal wire is introduced. The realization of auto-focusing and the realization of supermaterial of double-layer metal structure. (2) the double-ring (DR) structure composed of concentric rings is simulated and analyzed by using the finite-difference time-domain method (FDTD). The DR samples were prepared on 45 渭 m polyimide (PI) thin films by laser induced electroless plating. The THz-TDS results show that the DR structure has electromagnetically induced transparent (EIT) effect. A transparent window appears near 0. 42 THz. The Q value of the resonant peak is 12, which is an order of magnitude higher than that of the single ring. (3) A terahertz wave polarizer with double metal wire gate structure is designed and fabricated. Using 45 渭 m PI thin film as the substrate, the metal wire gate was fabricated on both sides of the substrate by laser induced electroless plating. The polarization performance of single and double-layer linear gate is compared by FDTD, and the effects of substrate thickness, metal thickness, substrate loss and offset between two layers on the (BWGP) performance of double-layer linear gate polarizer are analyzed. In the range of 0.2 ~ 1.6 THz, the transmittance of TM wave in BWGP is as high as 67 dB, and the extinction ratio is more than 45 dB, which is obviously higher than that of single-layer gate polarizer.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB39

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