title: Interferometric study on birds' feathers.
abstract: Optical techniques such as speckle pattern interferometry are well known in the nondestructive testing measurement community. They can be used, for instance, as a predictor of the mechanical behavior of a sample under study. However, in almost all circumstances, a mathematical model has to be applied in order to make sense of these measurements. This is a critical issue when an organic sample is studied, mainly due to its complex deformation response. A good example of this is observed in the birds' feathers. They have extraordinary mechanical and aerodynamic properties thanks to their stiffness and lightness. A couple of live birds are safely situated in front of an out-of-plane sensitive digital holographic interferometer (DHI), an optical system capable of recovering the optical phase in this type of nonrepeatable or unpredictable experiment. In order to recover the backscattering signal and its interferometric response, several images are recorded from different sections of the plumage. Displacement maps are obtained from what is, as far as is known, the first time that full field microdisplacement maps are presented over a hummingbird and a parakeet plumage.
authors.affiliation: Centro de Investigaciones en Óptica A.C. Loma del Bosque, 115 Lomas del Campestre, León, Guanajuato, México 37150. mandlti@cio.mx
authors.forename: Manuel H
authors.initials: MH
authors.lastname: De la Torre-Ibarra
authors.forename: Fernando Mendoza
authors.initials: FM
authors.lastname: Santoyo
mesh_terms: D000818:Animals; D001717:Birds; D005241:Feathers / Q000737:chemistry*; D006696:Holography / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007368:Interferometry / Q000379:methods*; D055620:Optical Phenomena; D012815:Signal Processing, Computer-Assisted; D014921:Wings, Animal / Q000033:anatomy & histology / Q000737:chemistry