Design And Key Technology Research Of Portable UV-VIS Spectrometer

Ultraviolet(UV)spectroscopy has become an effective instrument of detection to analyze the properties and chemical composition of substances.For example,a substance will excite a spectrum while a chemical reaction occurs.This spectrum is mainly located in the ultraviolet range.The monitoring and analysis of the spectra can be used to analyze the chemical reaction qualitatively and quantitatively.However,due to the absorption of photons in the ultraviolet region by the silicon substrate in the detector,it is difficult for ultraviolet light to generate signal charges in the detector.Therefore,the conventional spectrometer has a very low response to the ultraviolet band,which restricts the further development of ultraviolet spectrum detection.In response to the above requirements for UV spectroscopy,a portable wide-band UV-Vis spectrometer was designed.The key technologies of the thesis mainly include the following two parts.On one hand,our research team independently developed UV detectors,leading to an increase of the detector's UV response.On the other hand,the principle of the blazed grating in the spectrometer is studied so that the incident light energy in the ultraviolet band of the spectrometer is improved.Firstly,the principle of blazed grating and the diffraction theory in optical path system of spectrometer are studied.The influence of the blazed wavelength of blazed grating on ultraviolet band in the spectrometer is analyzed,and the energy loss in optical path of the spectrometer is reduced.The optical path of the portable UV-Vis spectrometer was designed according to the cross-type Czerny-Turner structure.Next,the materials and methods for preparing fluorescent film and performance parameters of the fluorescent film were investigated.Before the formal coating experiment,a mathematical model of fluorescent film was constructed to verify the parameters and properties of film and to prepare the theory for post-production UV-enhanced CCD.After the technology of the fluorescent film preparation was matured,the coated UVenhanced CCD was fabricated using the Lumogen fluorescent material and The Physical Vapor Deposition determined by the research.Then we set up a test system to test the parameters of the coated CCD and verify its enhanced UV performance.Finally,after designing the circuit,mechanical design and software,a portable UVVis spectrometer prototype was developed.The performance test results show that there is high resolution in the UV-Vis band and the spectral response in the UV band is increased by 20%.