集成二维多光栅光谱成像系统的研制及其应用

【作者】 韩涛；

【导师】 陈良尧；

【作者基本信息】 复旦大学 ， 光学， 2005， 博士

【摘要】 通过对包含丰富信息量的光谱特征进行分析和研究，可深刻理解众多信息光电子功能材料的结构和特性，所产生的现代光谱分析原理和方法在现代科学技术的许多领域获得了越来越广泛的应用，促进了信息技术的发展。针对高精度快速获取光谱的应用特点，本论文主要对集成二维多光栅成像光谱系统进行了研究，分别完成了新型面阵式CCD探测器型多光栅光谱分析和集成多光栅结构的高分辨快速红外光谱分析系统。论文对实验光谱分析系统的基本原理、设计和制备过程及其在在椭圆偏振光谱分析和高性能光电子薄膜生长系统中的应用进行了研究。本论文的主要内容如下：第一章介绍了光谱学原理及其实验系统发展的历史，以及在现代科学技术领域中的应用，对实验光谱系统的基本原理、基本结构和特点进行了有重点的叙述。第二章主要讨论了构成现代光谱系统的若干重要元器件的工作原理和结构，包括了关键的光栅等色散元件光栅，以及重要的光电探测器件，如CCD探测器和InGaAs光电二极管探测器等，还包括了滤色片和光谱系统的基本机构等内容。第三章详细介绍了本论文所研究和设计的新型面阵式CCD探测器型多光栅光谱分析系统，包括了实验原理、系统结构，以及实现多块光栅集成的光谱分析的具体方案等内容。研究中采用光谱折叠的方式，克服了面阵CCD探测器信号接受面有限张角的限制，实现了光谱的快速分析，并对光谱系统的实验测试结果进行了分析和讨论。第四章详细描述了本论文所研制的具有集成多光栅结构的高分辨快速红外光谱分析系统，可用于现代光通讯领域中的光谱信息的快速检测和分析。研究中采用了一个由五块子光栅组成的集成光栅结构和五个InGaAs红外线阵探测器，组成一个完整的装置，满足了宽波长区、高分辨率和快速光谱测量的要求，同时避免了机械扫描结构，使系统具有长时间工作稳定性、数据读取的高可靠性和快速读取数据等优点。该系统可用于高性能光电子功能薄膜的原位特性监控生长，包括对由四分之一波长和非四分之一波长光学厚度组成的混合薄膜结构的复杂特性进行实时监控。第五章进一步讨论了两种光谱分析系统在椭圆偏振光谱仪和高性能薄膜器件生长系统中的应用。详细介绍了将面阵式CCD探测器型多光栅光谱分析系统用于快速椭圆偏振光谱测量的实验装置，给出了系统的设计原理、结构和调试等过程，以及介绍了将集成二维多光栅快速红外光谱分析系统用于高性能光子薄膜器件制备的实验装置。更多还原

【Abstract】 In the modern information age, it has become very important to acquire data in a fast speed, especially in the field like the optical communication field where high-speed spectral analysis is required. For quick analysis of the spectrum with high resolution, instead of using a photomultiplier tube or a photon detector to detect the photons emerging from the narrow slit of the monochromator, a CCD array detector is placed at the focal plane of spectral output of the monochromator. The improved method has been performed to measure the optical signal in the entire spectral range without mechanically scanning the wavelength window during the operation. Instead of using a single grating to diffract the light, a three-grating structure,which has different groove spacing and blaze wavelengths for each grating, was demonstrated in the design. The light diffracted by these three plane gratings will form a folded spectrum, which is imaged on the two-dimensional focal plane of the CCD detector. The effective spectral range imaged on the detector is magnified three folds. By careful design of the system, the optical spectral measurements can be completed in the 200-1000 run wavelength range with high resolution at high speed of less than 0.1 s. The nonlinear relationship between CCD pixel position and wavelength is corrected with multiple polynomial functions in the calibration procedure, which fits the data using a mathematical pattern-analysis method. The instrument can be applied for rapid spectroscopic data analyses in many types of photo-electronic experiments and routine testing.In the telecommunication field, increasing use of the density wavelength-division multiplexing technology had resulted in great advance of the techniques to make the optical thin film device achieve very high quality with a sub-nanometer bandwidth in a nearly perfect square optical gate filtering pattern and work in a wider temperature range reliably. Except of complication in the film-structure design, the key issue in the advanced film deposition process is to precisely monitor and control the optical thickness of each film layer in the high density film stack with the optical parameters being accurately specified. Instead of measuring the light intensity at fixed single wavelength, therefore, more information with the light intensity, bandwidth, and line-shape that depend on many deposition parameters such as the layer thickness, optical constants and stress and so on should be obtained by measuring the spectra of the transmittance and reflectance in situ to control the entire spectral properties of multi-layered film structure accurately. It will be necessary to develop an opticalspectral measurement system that not only will work in a wider spectral range to monitor the entire spectral change in the film deposition process, but also will have a high spectral resolution being finer than the bandwidth of the thin film filter device and as well as have a fast data acquisition and analysis speed to match with the film growth rate in the vacuum condition.In order to achieve both the high spectral resolution and fast data acquisition speed, a new type of the spectrometer working in the infrared optical communication wavelength range (1450-1650 nm) has been studied, designed and constructed. The system was made by five InGaAs infrared line-array detectors and an integrated grating consisting of five sub-gratings. Without any mechanical scanning and moving parts, the full real-time spectral image of the sample can be obtained rapidly and accurately in about 20 ms and with a spectral resolution of about 0.08 nm. By analyzing the spectral features in a fast speed with excellent data repeatability, the system will have the advantage to be used in an advanced film deposition chamber to in-situ monitor and control the spectral properties and the growth process of the multi-layered film with an integral or a fractional quarter-wavelength layer structure precisely.Those works with great effort to study and design the new optical spectrometers have been described in detail to show their useful applications in the future.更多还原