Open AccessExperimental investigation of double-groove grating satisfying total internal reflection condition
Author(s) -
Takayuki Matsui,
Atsushi Miura,
Naoki Ikeda,
Hisayoshi Fujikawa,
Yoshimasa Sugimoto,
Nader Engheta,
Hideo Iizuka
Publication year - 2014
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.22.025362
Subject(s) - grating , optics , groove (engineering) , materials science , diffraction grating , nanolithography , diffraction , total internal reflection , reflection (computer programming) , resonance (particle physics) , guided mode resonance , coupling (piping) , wavelength , dielectric , rigorous coupled wave analysis , diffraction efficiency , transmission (telecommunications) , optoelectronics , physics , fabrication , medicine , alternative medicine , pathology , particle physics , computer science , metallurgy , programming language , electrical engineering , engineering
We experimentally demonstrate a TiO(2) double-groove grating coupler with two different groove widths on a SiO(2) substrate in the visible region. Tolerance investigations based on Bloch-mode profiles in the grating and coupling strengths between the Bloch modes and diffraction orders reveal that the transmission performance is robust when one of the paired ridges is narrow enough (60 nm and less) considering a typical nanofabrication accuracy. Moreover, the ridge shape affects weakly the transmission performance due to the non-resonance operation of our dielectric device. Such tolerance investigations together with current nanofabrication technology enable us to accomplish a 70% efficiency for coupling the normal incident light into the + 1st order transmission diffraction satisfying the total internal reflection condition at a 640 nm wavelength of operation.