Work

Determining optical material parameters with motion in structured illumination

Year: 2022

Type: article

Abstract: A set of power measurements as a function of controlled nanopositioner movement of a planar film arrangement in a standing wave field is presented as a means to obtain the thicknesses and the dielectric constants to a precision dictated by noise in an exciting laser beam and the positioning and detector process, all of which can be refined with averaging. From a mutual information perspective, knowing the set of positions at which measurements are performed adds information. While applicable to any arrangement of planar films, the implementation considered involves thin transmissive membranes, as are employed in applications such as optomechanics. We show that measured power data as a function of object position provides sensitivity to the film refractive index and far-subwavelength thickness. Use of a cost function allows iterative retrieval of the film parameters, and a multi-resolution framework is described as a computationally efficient procedure. The approach is complementary to ellipsometry and could play an important role in routine film characterization studies for fields involving solid state material processing, as is common in the semiconductor device field.

Source: Optics Express

DOI: 10.1364/oe.471763

Authors: Dergan Lin, Vivek Raghuram, Kevin J. Webb

Institution: Argonne National Laboratory

Language: English

Topic: Optical measurement and interference techniques

Subfield: Computer Vision and Pattern Recognition

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: National Science Foundation, Air Force Office of Scientific Research