Near-infrared broadband Si:H/SiO2 multilayer gratings with high tolerance to fabrication errors. (12th May 2020)

• Record Type: Journal Article
• Authors: He, Tao; Zhang, Jinlong; Jiao, Hongfei; Wang, Zhanshan; Cheng, Xinbin
• Is Part Of: Nanotechnology. Volume 31:Number 31(2020)
• Publication Date: 2020-05-12
• Subjects: thin films -- gratings -- fabrication tolerance; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ab8768
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Si:H and TiO2 multilayer dielectric gratings (MDGs) were studied comparatively to highlight the influence of refractive indices on fabrication tolerances, including tolerances for grating width errors and cross-sectional shape errors. The fabrication tolerance of Si:H MDGs is two to four times greater than that of TiO2 MDGs, because the higher refractive index of Si:H has a stronger ability to restrain electric fields. It was further revealed in these studies that a Si:H MDG with positive trapezoidal errors has minor influence on high diffraction efficiency bandwidth. Finally, a Si:H MDG was prepared without iterative corrections. Although large fabrication errors of grating width and cross-sectional shape existed, the MDG still had a 146 nm bandwidth with diffraction efficiency over 97%, which verifies the robustness of the proposed Si:H MDG.