Open AccessAngle-resolved spectral reflectometry with a digital light processing projector
Author(s) -
Garam Choi,
Mingyu Kim,
Jin–Yong Kim,
Heui Jae Pahk
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.405204
Subject(s) - optics , reflectometry , projector , collimated light , viewing angle , cardinal point , materials science , physics , computer science , computer vision , liquid crystal display , time domain , laser
We describe a novel approach for angle-resolved spectral reflectometry using a digital light processing (DLP) projector. Here, the DLP generates ring patterned images which are projected on the back focal plane of an objective lens. This way, the proposed method quickly changes the angle of incidence with ease based on the relation between the radius of the back focal plane and the angle of incidence. As a result, a detector captures the intensity of the image plane based on the angular and spectral axis. As the proposed method detects the interesting spot of a sample image, it can easily locate the measurement spot with viewing the full field of view, and the spot size is reduced by adopting the fiber. This method is verified by comparing the measurement output of the thin-film samples with a commercial ellipsometer. The result shows that our the proposed method enables the high accuracy of the thin-film inspection.