Experimental Study On Hyperspectral Imaging System Based On Acousto-Optic Tunable Filter

Since French physicist Brillouin first proposed the concept of acousto-optic interaction in 1922, and in 1969, Harris and Wallace worked together to design a acoustic-optic tunable filter(AOTF) for the first time in the world,and then on 6th,September 2008,we China successfully launched the first environment and disaster monitoring and forecasting satellite into space orbit,the primary payload of which is"HJ-1-A satellite hyperspectral imager"developped by XiAn Institute of Optics and Precision Mechanics of CAS, we can see, after decades of development, spectral imaging technology has been widely used in the space environmental remote sensing, fine agriculture, food online-monitoring, biomedical and some other fields, but also attracted the attention of many researchers at home and abroad.Imaging and spectroscopy are the two important areas of photovoltaic technology, their respective development and application have been very mature. Imaging technology pursues high spatial resolution,while the pursuit of spectroscopy technology is high spectral resolution. Capabilities of spectral imaging in these two areas are very prominent,that means it realizes the perfect combination of the two technologies.Firstly, in this paper, a large number of papers at home and abroad with respect to spectral imaging technology are for referance. On the basis of this, the current situation and development trend of spectral imaging technology in the world is analyzed, combined with laboratory existing conditions, the main research content and significance is made clear.Secondly, the working principle of noncollinear AOTF is described in detail. AOTF operates on the extraordinary Bragg diffraction. All of us are clear with the working principle and the main technical parameters through the introduction of these basic theories. The parallel tangential momentum-matching are also introduced. These theories have made a stable foundation for the following study.Thirdly, the front-end imaging optical lenses and back-end lenses needed in the hyspectral imaging system are designed. They are another important components besides the AOTF. The main function of the optical system is collecting the target areas or objects into the system and, ultimately, imaging in the CCD camera to obtain spectral information and spatial information of objects. The paper illustrates seriously how to design the optical system using ZEMAX.Finally, the paper verifies the overall performance of the system by imaging and spectral resolution experiments, and proves the feasibility of the designed optical system, has a referance value for further optimization of the whole system.