Ogata Y, Kolchiba M. Side edge emission from a waveguide substrate.
APPLIED OPTICS 2021;
60:9668-9671. [PMID:
34807149 DOI:
10.1364/ao.438330]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
In this study, we fabricated embedded titanium dioxide (TiO2) nanograting structures with slanted cross section on a silicon dioxide (SiO2) substrate using electron beam lithography (EBL) and reactive ion etching (RIE) methods, and we analyzed their optical signals. The surface morphologies of the embedded TiO2 nanograting structures were monitored by a scanning optical microscope (SEM). By focusing the transverse electric (TE) polarized beam with the wavelength λ=633nm at the incident angle θ=22.0∘ from the rear side of TiO2 face, we could observe +1st and -2nd diffraction orders with diffraction efficiencies (I/Itotal): I1=23% and I2=19%, respectively, on a SiO2/TiO2 interface. Diffraction beams were waveguided to both left and right directions in a SiO2 substrate via total internal reflection (TIR); next, two guided beams were emitted from the side edges of the substrate. This work is expected to develop a highly efficient two-way waveguide optical interconnector.
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