White light interference microscopy system design

Sébastien Marbach (1) , Christophe Cordier (1) , Rémy Claveau (2) , Thierry Engel (1) , Paul Montgomery (1) , Manuel Flury (1)

1 ICube - Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie
2 UCL - University College of London [London]

Interference microscopy is a non-destructive full-field imaging method, mainly used to measure the surface topography of different samples. In this work, two designs for improving the signal quality are described. The first consists of an original vertically orientated breadboard interferometer, in a Linnik configuration. The mechanical design of the arms allows the independent control and alignment of the coherence and the focal plane positions for optimizing fringe contrast. A low noise 16-bit camera is used to improve the sensitivity. The second interferometer is based on a Thorlabs tube system, with a Nikon Mirau Objective and a white LED, all controlled with IGOR Pro software or Labview, with the aim of being more compact, flexible and mobile. For both systems, an evaluation of the interferometric signal quality is performed, whereas the difference in lateral resolution by considering the 3D nature of the interferometric system, or only its 2D imaging abilities, is explored.

Mots clés: White Light Interferometry; Köhler Illumination; Linnik; Mirau; Phase Shifting Interferometry; Coherence Scanning Interferometry; Resolution Limit; Optical Metrology

Domaines: Optique / photonique; Instrumentations et Détecteurs [physics.ins-det]

Sébastien Marbach, Christophe Cordier, Rémy Claveau, Thierry Engel, Paul Montgomery, et al.. White light interference microscopy system design. SPIE Photonics Europe, SPIE, Apr 2020, Strasbourg (on line), France. pp.113521B-1, ⟨10.1117/12.2555929⟩. ⟨hal-03100903⟩