journal article·2023-05-23Open access

Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO3 Waveguides

Dmitrii Moskalev, Andrei Kozlov, Uliana Salgaeva, Victor Krishtop, Anatolii Volyntsev

Applied Sciences· Volume 13· Issue 11

Abstract

Photonic integrated circuits (PIC) find applications in the fields of microwaves, telecoms and sensing. Generally, PICs are fabricated on a base of isotropic materials such as SOI, Si3N4, etc. However, for some applications, anisotropic substrates such as LiNbO3 are used. A thin film of LiNbO3 on an insulator (LNOI) is a promising material platform for complex high-speed PICs. The design and simulation of PICs on anisotropic materials should be performed using rigorous numerical methods based on Maxwell’s equations. These methods are characterized by long calculation times for one simulation iteration. Since a large number of simulation iterations are performed during the PIC design, simulation methods based on approximations should be used. The effective index method (EIM) is an approximation-based method and is widely applied for simulations of isotropic waveguides. In this study, the applicability of EIM for simulations of anisotropic waveguides is analyzed. The results obtained by EIM are compared with the calculation results of a rigorous finite-difference frequency-domain (FDFD) method for evaluation of the EIM’s applicability limits. In addition, radiation losses in waveguides with rough sidewalls are estimated using the Payne–Lacey model and EIM. The results demonstrate the applicability of EIM for the simulation of anisotropic LNOI-based waveguides with cross-section parameters specified in this paper.
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Research context

OpenAlex topics: Photonic and Optical Devices · Photonic Crystals and Applications · Advanced Photonic Communication Systems

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, Russia

Department of General Physics, Perm National Research Polytechnic University, 614990 Perm, Russia

Funding

Ministry of Science and Higher Education of the Russian Federation

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