Optical System Design Of A Miniature UV Spectrometer And Study Of UV-Enhancement Technology Of Its Detector

Recently, the miniature UV Spectrometer is widely used in analytical chemistry, pesticide residues detection, water quality monitoring and other fields. The demand for its performance such as aberration, resolution and spectrum range grows continuously. In this paper, asymmetrical crossed Czerny-Turner (C-T) structure was adopted to the optical system design of the miniature UV Spectrometer, and the ZEMAX software was used to simulation, image quality evaluation and optimization of the optical path. Then the UV sensitization technology of CCD was studied to enhance its UV response. Removed the surface protection glass, based on the method of spin coating, deposited the phosphor powder Lumogen S 0795 onto the image surface of CCD. The UV-visible light conversion is realized by fluorescence effect, and the UV spectrum response of CCD is enhanced. Manufactured and installed a miniature UV spectrometer prototype based on the above optical design. By comparing the different UV responses of film-coated CCD and film-uncoated CCD in the miniature UV spectrometer prototype, The UV sensitization technology was evaluated and the changing of system resolution caused by film-coated CCD was studied. The main contents are as follows:1. The optical system of the miniature UV spectrometer was designed based on the asymmetrical crossed Czerny-Turner (C-T) structure and the theoretical resolution of the spectrometer was discussed. Using ZEMAX software to simulate, optimize and evaluate image quality of the optical path. Simulation results show the optical resolution is better than 0.5 nm at 180-270 nm and the best resolution is 0.1 nm at 180 nm, when used 30?m slit and 1800 grooves/mm planar reflection grating. Aberration diagrams show the image of stripe is regular and focused in the dispersion direction, and all kinds of aberrations are controlled in the capacity, the transmission efficiency is above 50%when the spatial frequency is 51p/mm.2. Phosphor powder Lumogen S 0795 from BASF corporation (German) was adopted to mix with organic solvent nitro-cotton and anhydrous alcohol in the proportion of 0.08g:0.7g:0.3g. Then used the phosphor powder solution to film the glass substrate and photosensitive surface of TCD 1304 linear array CCD based on spin coating method. Controled the film thickness, uniformity and surface smoothness effectively.3. Manufactured a miniature UV spectrometer prototype, and the optical system was assembled and adjusted by using halogen tungsten lamp, low-pressure mercury lamp and deuterium lamp. The different UV discrete and continuous spectrum response of film-coated CCD and film-uncoated CCD was compared in the same wavelength range of 217-318 nm. Based on test data analysis, the relative enhancement factor of UV response of film-coated CCD is 8.7 times higher than that of film-uncoated CCD, and the short-wavelength limit blue shifts from 310 nm to 200 nm, the intensity of visible spectrum has hardly changed at the same time, and the D-value of pixel resolution of the 365 nm spectral line between film-coated CCD and film-uncoated CCD is 3 pixel. All the data analyses show that, the UV-sensitization experimental method for CCD adopted in this paper, enhanced the UV response of front-illuminated linear CCD without affecting the transmission of visible light and the spectral resolution of the spectrometer.