Optical Design And Research Of Portable Ultraviolet Raman Spectrometer

Raman spectrometer is an important optical instrument for spectroscopic analysis and research,which can reflect the inherent vibration and rotational energy level structure of matter specifically,so as to obtain information about the structure of matter.Traditional spectrometers are large in size and have severely limited application range,and portability and miniaturization have become the development trend of Raman spectrometers.On the other hand,compared with the current research more visible light and near-infrared Raman spectrometer,ultraviolet Raman spectrometer can avoid the interference of fluorescent signals,stimulate stronger Raman signals,in resonant Raman technology research and biochemical detection shows a unique advantage.However,due to the speciality of optical circuit design and optical devices,the research of portable UV Raman spectrometer is still in its infancy.In this paper,the optical design of portable UV Raman spectrometer is studied,and the main results are as follows:(1)Based on the optical atrophy theory of the spectrometer,the optical design of the portable UV Raman spectrometer is carried out by using the optical design software Zemax.Using 266nm of ultraviolet light as a laser light source,the typical optical path structure of two portable Raman spectrometers,asymmetric Czerny-Turner and cross-Czemy-Turner,is designed.Both structures have better optical resolutions than 0.1nm in the operating bands of 270 to 290nm,with the asymmetric Czerny-Turner structures having a more stable resolution.(2)The principle of image dispersion of portable UV Raman spectrometer is studied,the method of cylindrical mirror dissipation is introduced in the light path,and the asymmetric Czerny-Turner optical path structure of ablation is designed.The results show that the adverb of the spatial dimension in the initial light path after the introduction of the cylindrical mirror is corrected,the mean square root radius(RMS)of the point column in the working band is less than 10μm,and the modulation transfer function(MTF)is above 0.7.(3)According to the characteristics of portable UV Raman spectrometer,select the key optics suitable for working in the ultraviolet band,including collimator,focus mirror,diffraction grating,optical detector,etc.Based on the above device,the asymmetric Czerny-Turner optical path structure is constructed,and the matching of optical path elements,the adjustment of optical optical axis and the propagation and commissioning of beam in the spectrometer are completed.