Triangular Pyramid Microstructure Array has the obvious effect that the light can be emitted uniformly. We use hot embossing technology to produce the Triangular Pyramid Array on PMMA, which the period of microstructure is 50μm and the height is 20μm. The film can replace spherical micromirror array film, and then the transmission of light can be improved by 2.2%. The results showed that under certain temperature conditions there is a matching relation between PMMA and mold about the thermal expansion coefficient, and the pressing temperature has great influence on the roughness of the microstructure surface.
For 320x240 pixel2 uncooled focal plane array detector, an infrared continuous zoom optical system of 10x zoom ratio for long-wavelength is designed in this paper. This system can be applied in joint transform correlator and other infrared tracing systems. The spectral band of the system is 8μm~12μm, the focal length is 20mm ~200mm , and the F number of the system is 2. The relative aperture is invariant during the zoom process, and the variable magnification curve and compensation curve are smooth as well. The system only consists of 7 lenses and one aspherical surface. The results have shown that when the maximum spatial frequency is 17lp/mm, the MTF(Modulation Transfer Function) curves in the whole range of focal length are all above 0.5 which are closed to diffraction limited curve. The stability of image plane is well, and the imaging quality is perfect, which show that the system meets the requirement of technical specification.
On the basis of optical correlation detection, photoelectric hybrid joint transform correlator(JTC) is widely used in military, aviation and intelligentization, etc. It has the advantages of great flexibility and high precision of recognition. However, the optical system which is in front of joint transform correlator(JTC) is applied to receive the infrared radiation of the target. It also has a certain influence on JTC’s detecting precision and tracking ability. Dual band infrared imaging system can receive different wave band of infrared radiation. Therefore, the image quality of optical system plays an important role in the joint transform correlator(JTC). According to the requirements of the joint transform correlator (JTC), the processes of optical design including the allocation of parameters and the selection of initial structure are presented. The infrared dual band coaxial telephoto system is designed for target detection. The system which is composed of four lenses can image in both 3μm~5μm and 8μm~12μm wavebands. The focal length is 200 mm and the relative aperture is 1:3. The system has the characteristics of small volume and compact structure. The optical system image quality is evaluated with ZEMAX optical design software. The results have shown that MTFs of the system are 0.62 and 0.35 for both wavebands respectively at 17lp/mm of spatial frequency which are closed to the diffraction limited curve. The relative aperture, field of view, and focal length are same for both spectral regions. The system meets the requirements of technical specification and improves the ability of JTC in target tracking and recognition.
In recent years, with the occurrence of photoelectric sensitive devices such as charge-coupled device (CCD) and
electrical addressed liquid crystal display (EALCD), particularly with the development in the computer technology,
digital holography interferometry has been developing rapidly. Digital holography was one of the important techniques in the field of three-dimensional non-contact testing. In order to realize the digitalization and real-time of the holographic interferometry, the digital holographic interferometry system based on EALCD and CCD for displacement and three dimensional deformation measurement of objects is established. The hologram and reconstructed hologram are recorded by CCD. The hologram is reconstructed by EALCD instead of holographic plate. The interference fringes which caused by micro displacement and deformation has been realized by this system. The reconstruction images of objects and holographic interference fringes are all preferable. In this paper, the holographic reconstruction and interference fringe has been enhanced and denoised by compiling program based on MATLAB and C++ in digital image processing. The single algorithm cannot meet the requirement of the experiment, so various algorithms were used in combination in order to enhance image quality and make interpretation and calculation more convenient. The straight fringes reflect the micro displacement of the object, the bending fringes represent the deformation of the object. Based many advantages of CCD and EALCD, the actual holographic interferogram with high contrast can be obtained quickly in our experiments, which the precise measurement of micro displacement and three-dimensional deformation of objects can be acquired