【摘要】 增大光学系统的景深已成为一项有意义的研究主题。根据轴锥镜的线焦特性,阐述了基于轴锥镜的大景深成像系统的基本原理。简单讨论了点光源在透镜前不同位置时系统点扩散函数的形式,并分析出其形状随点光源距透镜距离的改变而变化。利用无衍射光束的形成条件,推导出系统景深的计算公式。对于由半径为15 mm,锥角为0.01 rad的轴锥镜和焦距为125 mm的透镜组成的成像系统,其焦深可达336 mm。实验结果表明用轴锥镜能增大光学系统的景深。更多还原

【Abstract】 It has been an active research topic to extend the depth-of-field of optical imaging systems.The axicon that can image a point into a line segment along the optical axis can be used to extend the depth-of-field of an imaging system,and the imaging theory was explored.The forms of point spread function are briefly discussed when the point source at different positions along the optical axis,and they are changed with the distance between the point source and the lens.The calculation method of depth-of-field is also deduced based on the producing conditions of non-diffracting beams.For an imaging system composed of a lens with focal length f=125 mm and an axicon with radius r=15 mm,cone angle θ=0.01 rad,the depth-of-field is 232 mm.Experimental results validate the effect and feasibility of this method.更多还原