Nugent Keith A, Arhatari Benedicta D, Peele Andrew G
School of Physics, The University of Melbourne, Vic. 3010, Australia.
Ultramicroscopy. 2008 Aug;108(9):937-45. doi: 10.1016/j.ultramic.2008.03.008. Epub 2008 Apr 4.
Optical coherence theory is used to describe image formation in a telecentric optical system. By assuming a weakly interacting object and by considering points that are not too far from the optical axis, an optical transfer function description is obtained for imaging both the phase and the amplitude components of the object. A dimensionless coordinate system is identified to allow the transfer functions to be expressed independently of the details of the imaging system. Phase-contrast imaging is found to have an essentially coherent behaviour when the coherence length is a factor of 15 larger than the system resolution, and that the coherent region of the illumination therefore does not need to encompass the object.
光学相干理论用于描述远心光学系统中的图像形成。通过假设物体相互作用较弱，并考虑离光轴不太远的点，可获得物体相位和幅度分量成像的光学传递函数描述。确定了一个无量纲坐标系，以使传递函数能够独立于成像系统的细节来表示。当相干长度比系统分辨率大15倍时，发现相衬成像具有基本相干的行为，因此照明的相干区域不需要覆盖物体。
