Paper
27 March 2022 Waveguide mode conversion on anisotropic thin film lithium niobate
Yuan Shen, Lin Ai, Bigeng Chen, Yunjiang Rao
Author Affiliations +
Proceedings Volume 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications; 121698C (2022) https://doi.org/10.1117/12.2625112
Event: Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 2021, Kunming, China
Abstract
Thin film lithium niobite on insulator (LNOI) is attracting intensive attention in the field of integrated photonics owing to multiple advantages such as wide transparent window, low optical loss, high electro-optic coefficients and wafer-scale processing capability. On-chip integrated photonic devices based on LNOI promise low manufacturing cost and high performances. Meanwhile, compared with the conventional integrated photonics materials (Si, SiN, InP and so on), optical anisotropy of LNOI is presented as an outstanding feature which demands extra care for opto-electronics application but also provides the opportunity to develop novel devices. Refractive index of LNOI may change significantly depending on light propagation direction, wafer crystal orientation and polarization. Here, we investigate waveguide mode hybridization and mutual conversion in ridge waveguide on X-cut thin film LNOI. Properties of fundamental modes as well as higher-order modes are analyzed with varied structural parameters and propagation direction systematically by numerical simulation. It is found that, while mode conversion between two fundamental polarized modes is rather weak, conversion efficiency between TM0 and TE1 can be quite high in a bent waveguide. A mode convertor based on 90° bend is thus proposed, which converts TM0 mode to TE1 mode with an efficiency over 90% due to the strong optical anisotropy of LNOI. An optimized structure that replaces no-coupling arc section with smaller-radius one is also demonstrated with reduced size. Such mode converter using bent waveguide with anisotropy may find applications on novel LNOI photonic circuits and devices.
© (2022) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuan Shen, Lin Ai, Bigeng Chen, and Yunjiang Rao "Waveguide mode conversion on anisotropic thin film lithium niobate", Proc. SPIE 12169, Eighth Symposium on Novel Photoelectronic Detection Technology and Applications, 121698C (27 March 2022); https://doi.org/10.1117/12.2625112
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Waveguides

Waveguide modes

Thin films

Refractive index

Anisotropy

Geometrical optics

Integrated photonics

Back to Top