Chung, H.P.Lee, Chieh-HsunHuang, K.H.Yang, S.L.Wang, KaiSolntsev, AlexanderSukhorukov, AndreySetzpfandt, FrankChen, Y.H.2020-03-302020-03-301094-4087http://hdl.handle.net/1885/202498We report, to the best of our knowledge, the first broadband polarization mode splitter (PMS) based on the adiabatic light passage mechanism in the lithium niobate (LiNbO3) waveguide platform. A broad bandwidth of ~140 nm spanning telecom S, C, and L bands at polarization-extinction ratios (PER) of >20 dB and >18 dB for the TE and TM polarization modes, respectively, is found in a five-waveguide adiabatic coupler scheme whose structure is optimized by an adiabaticity engineering process in titanium-diffused LiNbO3 waveguides. When the five-waveguide PMS is integrated with a three-waveguide “shortcut to adiabaticity” structure, we realize a broadband, high splitting-ratio (ηc) mode splitter for spatial separation of TE- (H-) polarized pump (700-850 nm for ηc>99%), TM- (V-) polarized signal (1510-1630 nm for ηc>97%), and TE- (H-) polarized idler (1480-1650 nm for ηc>97%) modes. Such a unique integrated-optical device is of potential for facilitating the on-chip implementation of a pump-filtered, broadband tunable entangled quantum-state generator.Ministry of Science and Technology of Taiwan (MOST) (106-2221-E-008-068-MY3, 107- 2911-I-008-501, 107-2627-E-008-001, and 104-2923-E-007-001-MY4); German Academic Exchange Service (Project-ID 57334258); Australia-Germany Joint Research Cooperation Scheme.14 pagesapplication/pdfen-AU© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved. https://www.osapublishing.org/submit/review/copyright_permissions.cfm#posting (Publisher journal website 30/3/2020)https://www.osapublishing.org/library/license_v1.cfm#VOR-OA2019-01-2110.1364/OE.27.0016322022-09-11An OSA-formatted open access journal article PDF may be governed by the OSA Open Access Publishing Agreement signed by the author and any applicable copyright laws. Authors and readers may use, reuse, and build upon the article, or use it for text or data mining without asking prior permission from the publisher or the Author(s), as long as the purpose is non-commercial and appropriate attribution is maintained.