Immediate and one-point roughness measurements using spectrally shaped light

• Published in: Optics express Vol. 30; no. 10; pp. 16078 - 16093
• Main Authors: Buet, Xavier, Zerrad, Myriam, Lequime, Michel, Soriano, Gabriel, Godeme, Jean-Jacques, Fadili, Jalal, Amra, Claude
• Format: Journal Article
• Language: English
• Published: Optical Society of America - OSA Publishing 09-05-2022
• Subjects: Physics
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.450790

Capitalizing on a previous theoretical paper, we propose a novel approach, to our knowledge, that is different from the usual scattering measurements, one that is free of any mechanical movement or scanning. Scattering is measured along a single direction. Wide-band illumination with a properly chosen wavelength spectrum makes the signal proportional to the sample roughness, or to the higher-order roughness moments. Spectral shaping is carried out with gratings and a spatial light modulator. We validate the technique by cross-checking with a classical angle-resolved scattering set-up. Though the bandwidth is reduced, this white light technique may be of key interest for on-line measurements, large components that cannot be displaced, or other parts that do not allow mechanical movement around them.