RT conferenceObject
T1 Episcopic coaxial illumination device for the simultaneous recording of the speckle signature in the spectrum and in the image of scattering reflective surfaces
A1 Fernández Fernández, José Luis
A1 López Vázquez, José Carlos
A1 Trillo Yáñez, María Cristina
A1 Fernández Doval, Ángel Manuel
K1 3311.11 Instrumentos Opticos
K1 2209.19 Óptica Física
AB Inspection  of  optically  rough  surfaces  in  search  of  defects  or  other  surface  features  with  deterministic  reflectance  distributions  is  a  subject  well  suited  to  optical  techniques.  We  present  a  device  with  episcopic  coaxial  illumination,  specifically  developed  for  such  kind  of  inspection  tasks,  which  simultaneously  renders  both  a  coherent  image  and  the  spatial  spectrum  of  a  portion  of  the  surface,  precisely  defined  by  the  illuminating  laser  spot.  It  is  based  on  the  well-known single-lens coherent image processing system, with beamsplitters added to insert the illuminating laser beam and to  allow  simultaneous  access  to  the  Fourier  transform  and  the  image  planes.  The  device  allows  inspecting  the  speckle  signature of surface features in both planes, thus allowing different defect recognition approaches. By selecting the size of  the  illuminated  area  of  the  object  or  the  lens  aperture,  different  speckle  sizes  can  be  obtained.  If  the  speckle  size  is  made large enough, identification of individual features can be made on the basis of their particular speckle signatures. Some envisaged applications are the characterization of defects or structures in rough surfaces, the evaluation of speckle statistics in precisely defined zones of surfaces or the identification of authentication marks.
YR 2012
FD 2012-09-11
LK http://hdl.handle.net/11093/213
UL http://hdl.handle.net/11093/213
LA eng
NO Ministerio de Economía y Competitividad y Comisión Europea (FEDER) | Ref. DPI2011-26163
DS Investigo
RD 09-oct-2024