【作者】 王文霞；

【导师】 何明霞；

【作者基本信息】 天津大学 ， 仪器科学与技术， 2012， 硕士

【摘要】 太赫兹波是一种波长介于红外与微波之间的电磁波,具有电磁学和光电子学两方面的特性,在自然界中广泛存在。太赫兹时域光谱技术是一种电磁辐射位相相干技术,利用飞秒脉冲激光泵浦产生和探测太赫兹电磁场辐射,能同时获得太赫兹脉冲的振幅和相位信息。因此,太赫兹时域光谱技术具有很高的时间分辨率和频域分辨率,光谱系统能达到很高的探测信噪比和较宽的探测带宽,可广泛应用于多种样品特征谱的检测。随着国内外太赫兹光谱仪器产品的发展和国家对科学仪器发展的重视,开发和研制具有自主知识产权的太赫兹时域光谱仪器对太赫兹科学技术的推广和应用研究具有重要意义。实用型、小型化、高性能正是目前太赫兹光谱技术仪器化研究发展的方向。本文结合实验室现有太赫兹时域光谱系统的特点,以实用化为主导方向,进行了实验室系统装置的仪器化工作。目前所做工作为第一代产品的研制,主要内容包括以下5个方面:1.结合光电导天线THz-TDS原理以及结构组成,对实验室原有太赫兹系统进行改进。采用小型光纤激光器泵浦产生飞秒激光脉冲;搭建了紧凑型的光纤光电导天线(Fiber Photoconductive Antenna, FPcA)THz-TDS系统;采用CD552-R3电路进行数据采集,用基于cy7c68013的USB模块进行数据通讯。以上改进在保证系统性能的同时缩小了系统体积。编写上位机控制界面,增加了中药图谱数据库,通过图谱比对可以进行中药样品的鉴定。2.设计并加工一款分层式结构的光谱仪外壳,将系统中的分立元件集中放置,对光路系统进行防振设计和密封设计,实现系统的仪器化。外壳选用高性能轻便的工程塑料ABS材料,系统整体尺寸小、重量轻,方便移动。3.制作了片剂样品连续检测装置和用于检测液体的三槽位式的比色皿架,方便用户进行多种形态样品的检测。设计由步进电机控制的二维平移台,实现样品二维扫描的自动控制,用于基底皮肤癌组织的扫描成像。4.对系统中可能存在的、由于延迟线倾斜造成的太赫兹实测谱线的线性缩放,采用高精度傅里叶红外光谱仪——布鲁克产品VERTEX 80的检测结果作为参考,对太赫兹频谱的线性缩放进行比对修正,取得了良好的效果。5.将仪器组装完毕后对仪器的整体性能进行评价和初步的测试,结果表明整体仪器可以进行样品的检测,并且操作舒适,人机环境友好。更多还原

【Abstract】 As an electromagnetic wave with wavelength between infrared and microwave, terahertz wave has characters with both electromagnetism and light electronics, which exists widely in nature. The terahertz time-domain spectrum technique is a kind of coherent detection of electromagnetic radiation. By using femtosecond pulse laser pumped to produce and detection terahertz radiation it can gain terahertz pulse amplitude and phase information. The time domain terahertz spectrum technology can be applied with a wide range of samples according the spectrum characteristics of detection. Developing and manufacturing terahertz spectral instrument with independent intellectual property rights is of great significance, so we work to make the terahertz spectral instruments practical, miniaturized and high performance, and the main content includes the following 5 aspects.1. Using optical fiber laser of small size pumped to produce femtosecond laser pulses; Setting up compact fiber photoconduction THz-TDS system; Using CD552-R3 circuit in data collection and cy7c68013 USB module in data communication.2. A spectrometer shell of hierarchical structure is designed to make the system antiquating and sealed. The shell is made of light engineering plastic- ABS, which makes the whole system of small size, light weight, and convenient to move.3. A continuous detector for testing tablet samples and a device for detecting liquid samples are made for users in detecting various forms of samples conveniently. By designing a stepping motor controller, make samples of 2-d scanning automatically.4. In odder to decrease the possible misregistration caused by the delay line tilt, we use the results of Fourier infrared spectrometer-- VERTEX 80 as standard baseline, to calibrate terahertz spectrum, and have obtained good effect.5. After the instrument’s assembling, we complete evaluating and preliminary testing of the overall instrument, and the results show that the overall instrument can be used to detect samples, with the operation comfortably and man-machine environment friendly.更多还原