Open AccessAnalysis and minimization of spacing error of holographic gratings recorded with spherical collimation lenses
Author(s) -
Shiwei Wang,
Lijiang Zeng
Publication year - 2015
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.23.005532
Subject(s) - zernike polynomials , optics , grating , wavefront , collimated light , spherical aberration , holography , interference (communication) , optical aberration , physics , materials science , mathematics , computer science , lens (geology) , laser , computer network , channel (broadcasting)
This research proposes a feedback method to adjust the dual-beam exposure system with spherical collimation lenses to achieve gratings with low spacing error. Through theoretical analysis and numerical calculation, it is proved that the interference aberration can be analyzed with the Zernike polynomials and the adjustment errors can be estimated according to the linear relationship between the errors and the polynomial coefficients. Moreover moving the substrate along its normal is proposed to decrease the spacing error but keep the grating's period unchanged. In the experiments, the wavefront measurement results of the ± 1st orders are used to deduce the spacing error. Based on the feedback adjustment method, the grating with a spacing error of 0.03 λ within 70 mm × 70 mm is fabricated with the collimation lenses of 0.6 λ spherical aberration.