Resolution, focus depth in the Fresnel-Fraunhofer domains

Francisco F. Medina; Roman Castaneda; Jorge Garcia-Sucerquia

doi:10.1117/12.668214

20 January 2006 Resolution, focus depth in the Fresnel-Fraunhofer domains

Francisco F. Medina, Roman Castaneda, Jorge Garcia-Sucerquia

Proceedings Volume 6027, ICO20: Optical Information Processing; 60272I (2006) https://doi.org/10.1117/12.668214
Event: ICO20:Optical Devices and Instruments, 2005, Changchun, China

Abstract

Defocused imaging can be analyzed as Fresnel diffraction. The defocus parameter, that characterizes this imaging, is related to an effective Fresnel number, which is induced by the geometry of the imaging set-up. From this point of view, perfectly focused images result from Fraunhofer diffraction. Therefore, the same criteria for distinguishing between Fraunhofer and Fresnel diffraction can be applied to determine if the image is or not focused. As a consequence, new definitions of the focus depth can be deduced. In addition, resolution of two point-objects under different states of spatial coherence and focus conditions is discussed and some resolution criteria are deduced. Then, they are compared to the classical resolution criteria, which are considered as applicable to the extreme cases of fully spatial coherence and fully spatial incoherence. Some classical examples, such as, imaging of one point object and two near point objects, are discussed to illustrate the analysis.

Citation Download Citation

Francisco F. Medina, Roman Castaneda, and Jorge Garcia-Sucerquia "Resolution, focus depth in the Fresnel-Fraunhofer domains", Proc. SPIE 6027, ICO20: Optical Information Processing, 60272I (20 January 2006); https://doi.org/10.1117/12.668214

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available