The Fiber Raman Spectrometer Construction And The Spectroscopic Properties Study Of Some Azo Materials

As a molecular spectroscopic technique, Raman spectroscopy is one of the important analytical tools in laboratory and widely used in biological analysis, cultural relics and archaeology, modern materials science due to the advantages of rapid, non-invasive, portable and easy to operate. However, there is much work still to be done from the laboratory to field application for Raman spectroscopy, especially in clinical diagnostics and field archaeology. Fiber Raman spectroscopy is considered to be the best solution to solve this problem. Currently, there are so many problems need to be solved in clinical diagnostics using fiber Raman spectroscopy. These problems include designing a flexible, miniature and efficient fiber Raman probe, suppressing the biological tissue fluorescence and fiber Raman background, developing an efficient classification algorithm, observing the intrinsic Raman spectroscopy of the biological tissue, developing early diagnosis software module and development the complete early disease diagnosis system. It has practical significance to resolve these problems for clinical diagnostics and promote the application of fiber Raman spectroscopy in other areas.Early diagnosis and blocking the occurrence, development and metastasis are the key to prevention and treatment of the upper gastrointestinal cancer which is a malignant disease endangering the health of our people. As an accurate, sensitive and effective optical diagnostic method, optical fiber Raman spectroscopy caused great concern in the early diagnosis of upper gastrointestinal cancer to many scientists. At present, the key task of the early diagnosis of upper gastrointestinal cancer using fiber Raman spectroscopy is designing a flexible, miniature and efficient fiber Raman probe, optimizing the Raman spectrometer system, in vivo exploratory detecting rat or human biological tissue and developing an efficient classification algorithm. It has not been found that the complicated and mature fiber Raman spectroscopy system for in vivo early clinical diagnostic. This thesis focus on building the prototype of the fiber Raman spectrometer for in vivo early clinical diagnosis upper gastrointestinal cancer and enriching the application of the Raman spectroscopy, results are summarized as follows:1. A multi-mode semiconductor laser with785nm and an imaging spectrometer system based on asymmetric Czerny-Turner system and a thermoelectric cooler near-infrared enhanced CCD detector with back-illuminated deep depletion were designed and customized according to the literature, theoretical and experimental simulation of the optical path. An outside optical path system was designed to match the fiber with spectrometer whose aperture value was2.3and4.1respectively. At last, the above optical elements and outside optical path system were composed of the main body portion of the fiber Raman spectrometer prototype.2. Three fiber Raman probes were designed and customized. The first probe with length of100mm and outer diameter of5.5mm adopted the classical spectrophotometric model. In order to increase the light collection efficiency, a ball lens with diameter5mm was mounted in the distal end. This fiber probe was used to in vivo and ex vivo detect the normal tissue, oral squamous cell carcinoma, gastric cancer tissues, breast cancer tissue and acupuncturepoints of human skin tissue. The second probe with length of50mm and outer diameter of5.2mm adopted the spectrophotometric configuration with three collection fiber around one stimulate fiber. In order to increase the light collection efficiency, a lens was mounted in the distal end. The third flexible and miniature probe with length of50mm and outer diameter of2.1mm adopted the spectrophotometric configuration with three collection fiber around one stimulate fiber. In order to increase the light collection efficiency, a lens was mounted in the distal end. It could in vivo detect the upper gastrointestinal cancer with the help of endoscope. A side view of fiber Raman probe with ball lens also designed.3. The late Qing Dynasty painted porcelains and a Tang Dynasty buddha were studied by a portable spectrometer combined with micro-Raman spectrometer and scanning electron microscopy coupled to energy dispersive spectroscopy. The results showed the portable spectrometer had a higher sensitivity with hematite and lapis lazuli compared with copper and lead oxide. Composition of these cultural relics also discussed.4. A series of nonlinear optical (NLO) azo-materials containing nitro. indole and sulfonyl based chromophores were studied in-depth by using Fourier transform (FT) IR, FT-Raman,!H nuclear magnetic resonance (NMR), UV-vis spectra and density functional theory (DFT). The large ? values calculated by the DFT methods showed that the studied molecules were good NLO materials, and the molecule which owns a larger substituent group had a larger value. The HOMO-LUMO gap and the relationship between the structure and nonlinear performance of these materials also discussed. Furthermore, simultaneous infrared and Raman activity suggests that intramolecular charges might transfer through the conjugated framework from the electronic donor group to electronic acceptor group.This thesis enriched the application of Raman spectroscopy in the filed of biomedical, outdoor archaeological and modern materials, and was expected to contribute to a wider range of practical applications.