The Study Of Hyperspectral Imaging System With Double Filtering Based On Single Tellurium Dioxide Crystal

The acousto-optic tunable filter is a new kind of spectroscopic element which can be electronically controlled.The crystal used is tellurium dioxide birefringent acousto-optic crystal,which is the most commonly used acoustooptic material in visible light and near infrared range,and has good acousto-optic properties.Tellurium dioxide is an excellent acousto-optic crystal,which is completely transparent in the visible light range.It works by the interaction between light waves and ultrasonic waves in the acousto-optic crystal.It has the advantages of small size,no moving parts,fast tuning response speed,high diffraction efficiency and low requirement on the operating environment.It is widely used in high spectral imaging,spectral detection and other hot fields.However,the spectral resolution of acousto-optic tunable filter is a limitation of its application.we developed a hyperspectral imaging system based on double filtering of single tellurium dioxide crystals.It has great theoretical significance to further improve the spectral resolution of acousto-optic tunable filters,and has practical significance to expand the application of acousto-optic tunable filters.In order to better study the performance of double filtering technology based on single crystal acousto-optic tunable filter in wide spectral range.The experiments were carried out in the visible light range,and the parameters such as spectral bandwidth,spectral side lobe and diffraction efficiency of single filtering and single crystal double filtering were measured respectively.The double filtering experimental system based on a single acousto-optic tunable filter is optimized,which can be used to study hyperspectral microscopic imaging in visible light range.Compared with the single filtering method,the single crystal double filtering system with a single acousto-optic tunable filter compressed the spectral bandwidth by 30.7% at the central wavelength of 626.15 nm,and the side lobe suppression of the diffraction light decreased from-9.96 d B to-19.67 d B.The experimental results demonstrated that single crystal double filtering has higher spectral resolution and higher spectral purity than single filtering.Hyperspectral imaging is an imaging technique that combines multispectral bands with image information.Its applications range from improving the diagnosis of cancer in medicine to testing the quality of products in industry.Here we introduced a single crystal double filtering technique that provided high-resolution hyperspectral microscopic images in a few minutes.A hyperspectral microscopic maging system was constructed based on an acousto-optic tunable filter.From the perspective of spectrum and imaging,the optimized system was analyzed in the visible light range.The spectral resolution was improved by 37.08% ? 59.95%.The side lobe was obviously inhibited and the purity of the spectrum was improved.In addition,the capability of the system in terms of spectral performance and image quality was evaluated using optical resolution target and unstained gastric cancer slices as two examples of hyperspectral microscopy.The hyperspectral microscopic imaging results of single filtering system and single crystal double filtering system are compared.In a word,the single crystal double filtering system has excellent performance in bandwidth compression and side lobe suppression.In particular,the single crystal double filtering technology of combining hyperspectral microscope with microscope was applied for the first time in the visible light range.