Open AccessWaveguides consisting of single-crystal lithium niobate thin film and oxidized titanium stripe
Author(s) -
Shuang Li,
Lutong Cai,
Yiwen Wang,
Yunpeng Jiang,
Hui Hu
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.23.024212
Subject(s) - lithium niobate , materials science , optics , titanium , waveguide , polarization (electrochemistry) , laser , etching (microfabrication) , optoelectronics , layer (electronics) , composite material , chemistry , physics , metallurgy
Strip-loaded waveguides were fabricated by the direct oxidation of a titanium film based on the single-crystal lithium niobate. The method avoided the surface roughness problems that are normally introduced during dry etching of waveguide sidewalls. Propagation modes of the composite strip waveguide were analyzed by a full-vectorial finite difference method. The minimum dimensions of the propagation modes were calculated to be 0.7 μm(2) and 1.1 μm(2) for quasi-TM mode and quasi-TE mode at 1550 nm when the thickness of the LN layer and TiO(2) strip was 660 nm and 95 nm, respectively. The optical intensity was as high as 93% and was well confined in the LN layer for quasi-TM polarization. In this experiment, the propagation losses for the composite strip waveguide with 6 μm wide TiO(2) were 14 dB/cm for quasi-TM mode and 5.8 dB/cm for quasi-TE mode, respectively. The compact hybrid structures have the potential to be utilized for compact photonic integrated devices.