Scribd is the worlds largest social reading and publishing site. Degagement au milieu m 5,5 7,8 12,4 17,5 21,4 24,7. We use fourwave mixing to record encrypted image into. In optics, the fresnel diffraction equation for nearfield diffraction is an approximation of the. Optical processor was implemented to encrypt images using fresnel diffraction in free space. Us navy 070406n43b083 n the flight deck aboard the aircraft carrier uss ronald reagan cvn 76, interior communications specialists assigned to air departments v2 division, calibrate the improved fresnel lens optical lan. Us navy 070406n43b083 n the flight deck aboard the aircraft carrier uss ronald reagan cvn 76, interior communications specialists assigned to air departments v2 division, calibrate the improved. Wolf, principles of optics, 1999, cambridge university press, cambridge. Estan fundamentadas en principios fisicos diferentes. Theoretical description of fiber bragg reflectors prepared by fresnel difraccion images. Cet effet est negligeable pour des liaisons inferieure a 1 km. Files are available under licenses specified on their description page. Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.
All structured data from the file and property namespaces is available under the. Pdf the type of diffraction that is generated when an aperture is illuminated with a spherical monocromatic wave depends on the optical setup. All structured data from the file and property namespaces is available under the creative commons cc0 license. Numerical calculation of near field scalar diffraction using. Free spectral range variations of gratingbased fabryperot filters photowritten in optical fibers. There are criteria to distinguish between fraunhofer and fresnel diffraction in. It is defined as the bending of waves around the corners of an obstacle or through an aperture into the. This page was last edited on 26 february 2019, at 00. It is defined as the bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacleaperture.