REFLECTIVE GRATING INTERFEROMETER FOR MEASURING THE FOCAL LENGTH OF ALENS BY DIGITAL MOIRE EFFECT

Citation
S. Denicola et al., REFLECTIVE GRATING INTERFEROMETER FOR MEASURING THE FOCAL LENGTH OF ALENS BY DIGITAL MOIRE EFFECT, Optics communications, 132(5-6), 1996, pp. 432-436
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Optics
Journal title
ISSN journal
0030-4018
Volume
132
Issue
5-6
Year of publication
1996
Pages
432 - 436
Database
ISI
SICI code
0030-4018(1996)132:5-6<432:RGIFMT>2.0.ZU;2-Z
Abstract
A new technique is proposed, based on digital moire effects,for measur ing the focal length of a lens. The test lens is illuminated by a vari able pitch interference pattern produced by an interferometer which ma kes use of a reflective diffraction grating, Moire fringes are generat ed by digitally adding the magnified images produced by the lens on th e original interference pattern. The focal length of the lens can be d etermined by counting the number of moire fringes. This technique is s uitable for measuring both long and short focal length lenses. The foc al lengths of both positive and negative lenses were experimentally me asured.