Author Affiliations
Abstract
1 Department of Instrument and Science in Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2 Ngee Ann Polytechnic, Singapore 599489, Singapore
Aperture synthesis is an important approach to improve the lateral resolution of digital holography (DH) techniques. The limitation of the accuracy of registration positions between sub-holograms affects the quality of the synthesized image and even causes the failure of aperture synthesis. It is a major issue in aperture synthesis of DH. Currently intensity images are utilized to find the registration positions of sub-holograms in aperture synthesis. To improve the accuracy of registration positions, we proposed a method based on similarity calculations of the phase images between sub-holograms instead of intensity images. Furthermore, a quantitative indicator, degree of image distortion, was applied to evaluate the synthetic results. Experiments are performed and the results verify that the proposed phase-image-based method is better than the state-of-the-art intensity-image-based techniques in the estimation of registration positions and provides a better synthesized final three-dimensional shape image.
digital holography synthetic aperture registration position phase image Chinese Optics Letters
2021, 19(7): 070501
中国科学院上海光学精密机械研究所信息光学研究室，上海 201800
基于Kogelnik的耦合波理论，研究了在色散效应的影响下，超短脉冲激光光束在反射型体全息光栅中衍射的性质．研究给出了衍射光及透射光在频谱域及时间域的振幅及强度分布、光栅的光谱宽度及衍射效率随光栅参量及入射条件的变化．数值研究的结果表明，在光栅记录介质色散效应的影响下，衍射光束的光谱宽度减小，脉冲展宽，衍射效率降低．通过适当的选取光栅参量及入射条件，可以控制衍射和透射光束的频谱和时间强度分布，得到满意的衍射和透射光束的带宽和波形，从而可以将其应用于脉冲整形等技术中．
衍射 耦合波理论 体全息光栅 超短脉冲光束 Diffraction Coupled wave theory Volume holographic grating Ultrashort laser pulsed beam
