Open AccessUltra-low loss ridge waveguides on lithium niobate via argon ion milling and gas clustered ion beam smoothening
Author(s) -
Shawn Yohanes Siew,
Eric Jun Hao Cheung,
Haidong Liang,
Andrew A. Bettiol,
Noriaki Toyoda,
Bandar Alshehri,
Elhadj Dogheche,
Aaron J. Danner
Publication year - 2018
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.26.004421
Subject(s) - lithium niobate , materials science , optics , argon , fabrication , ion milling machine , ion , refractive index , ion beam , etching (microfabrication) , beam propagation method , ridge , optoelectronics , beam (structure) , nanotechnology , chemistry , medicine , paleontology , physics , alternative medicine , organic chemistry , pathology , layer (electronics) , biology
Lithium niobate's use in integrated optics is somewhat hampered by the lack of a capability to create low loss waveguides with strong lateral index confinement. Thin film single crystal lithium niobate is a promising platform for future applications in integrated optics due to the availability of a strong electro-optic effect in this material coupled with the possibility of strong vertical index confinement. However, sidewalls of etched waveguides are typically rough in most etching procedures, exacerbating propagation losses. In this paper, we propose a fabrication method that creates significantly smoother ridge waveguides. This involves argon ion milling and subsequent gas clustered ion beam smoothening. We have fabricated and characterized ultra-low loss waveguides with this technique, with propagation losses as low as 0.3 dB/cm at 1.55 µm.