Design Of Polarized Laser Receiving Optical System Of Common Aperture With Four-channel Array Structure

Compared with the traditional intensity of the imaging system,polarization imaging system not only can get information about the target intensity information, but also can get target polarization information, enhance the contrast between target and background and improve the ability of target detection and identification. Thus, in recent years the rapid development of the polarization imaging technology,the technology is widely used in military and civil fields. In order to measure a moving target and get images of complete Stokes polarization imaging, simultaneous imaging method is proposed and become the key technology of real-time measurement of target polarization information.In this paper, a common aperture with four-channel array polarized laser receiving imaging system is designed by studying Stokes polarization imaging method and analyzing several current common polarization imaging systems. The system is based on the complete polarization imaging method and the technology of aperture segmentation.In order to achieve simultaneous polarization imaging, an array of four-channel configuration is used which can obtain the intensity image of the target four different polarization components in the system. The focal length of the optical system is 300mm, F number is 2, and operating wavelength is 1.06μm. The modulation transfer function in the spatial frequency 611p/mm is higher than 0.4 which close to the diffraction limit and the spot RMS radius in each field of view is less than pixel size after the system optimization. The laser is affected by atmospheric turbulence when polarization imaging system on a faraway target imaging, then the laser will generate wavefront aberration during transmission. A blurring and shaking target image is generated in the image plane of the optical system if the wavefront aberration is not corrected. Therefore, a four-channel array polarized imaging adaptive optics system is designed based on the common aperture with four-channel array polarized laser receiving imaging system. In the design process,closed loop adaptive system is matched to the common aperture with four-channel array polarized laser receiving imaging system by applying the adaptive compensation technology. The focal length of the optical system is 364mm, F number is 2.5, operating wavelength is 1.06μm, and half-field angle is ±0.3°. The MTF lines close to the diffraction limit and the image points in each field spot diagram are concentrated in a single detector range in the system.Design results show that the imaging quality of both systems approach to diffraction limited and their imaging quality meet the required performance.