Use of a phase type elongated circular grating in Talbot moiré deflectometry
Abstract:We analyze theoretically and experimentally the self-image of a phase type elongated circular (EC) grating which has a periodic structure of rectangular type, so that it can be employed in Talbot moiré deflectometry. We examine the visibility of a self-imaged phase EC grating while the optical phase difference of the grating is varied. We show that the self-image of a phase EC grating of rectangular type is slightly aberrated around the center of the interface of linear and semicircular parts but moiré fringes by self-imaging a phase EC grating on a reference EC grating are little influenced by the image aberration. We conclude that a phase EC grating as well as an amplitude EC grating in our earlier work [Optik 113 (2002) 285] can be effectively applied to a Talbot interferometer when the phase difference of the grating is prepared close to 90°.
Document Type: Research Article
Publication date: June 1, 2004