Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides
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, Si<sub>3</sub>N<sub>4</sub>, etc. However, for some applications, anisotropic substrates such a...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/13/11/6374 |
| _version_ | 1797597937674485760 |
|---|---|
| author | Dmitrii Moskalev Andrei Kozlov Uliana Salgaeva Victor Krishtop Anatolii Volyntsev |
| author_facet | Dmitrii Moskalev Andrei Kozlov Uliana Salgaeva Victor Krishtop Anatolii Volyntsev |
| author_sort | Dmitrii Moskalev |
| collection | DOAJ |
| description | 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, Si<sub>3</sub>N<sub>4</sub>, etc. However, for some applications, anisotropic substrates such as LiNbO<sub>3</sub> are used. A thin film of LiNbO<sub>3</sub> 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. |
| first_indexed | 2024-03-11T03:12:20Z |
| format | Article |
| id | doaj.art-506d4f0171914d5a8ad47847ffd8baac |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T03:12:20Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-506d4f0171914d5a8ad47847ffd8baac2023-11-18T07:31:17ZengMDPI AGApplied Sciences2076-34172023-05-011311637410.3390/app13116374Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> WaveguidesDmitrii Moskalev0Andrei Kozlov1Uliana Salgaeva2Victor Krishtop3Anatolii Volyntsev4Department of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, RussiaDepartment of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, RussiaDepartment of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, RussiaDepartment of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, RussiaDepartment of Nanotechnology and Microsystem Techniques, Faculty of Physics, Perm State University, 15 Bukireva Str., 614068 Perm, RussiaPhotonic 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, Si<sub>3</sub>N<sub>4</sub>, etc. However, for some applications, anisotropic substrates such as LiNbO<sub>3</sub> are used. A thin film of LiNbO<sub>3</sub> 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.https://www.mdpi.com/2076-3417/13/11/6374anisotropic waveguideseffective index methodfinite-difference frequency-domain methodthin film of lithium niobate on insulatorphotonic integrated circuitsradiation losses |
| spellingShingle | Dmitrii Moskalev Andrei Kozlov Uliana Salgaeva Victor Krishtop Anatolii Volyntsev Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides Applied Sciences anisotropic waveguides effective index method finite-difference frequency-domain method thin film of lithium niobate on insulator photonic integrated circuits radiation losses |
| title | Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides |
| title_full | Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides |
| title_fullStr | Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides |
| title_full_unstemmed | Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides |
| title_short | Applicability of the Effective Index Method for the Simulation of X-Cut LiNbO<sub>3</sub> Waveguides |
| title_sort | applicability of the effective index method for the simulation of x cut linbo sub 3 sub waveguides |
| topic | anisotropic waveguides effective index method finite-difference frequency-domain method thin film of lithium niobate on insulator photonic integrated circuits radiation losses |
| url | https://www.mdpi.com/2076-3417/13/11/6374 |
| work_keys_str_mv | AT dmitriimoskalev applicabilityoftheeffectiveindexmethodforthesimulationofxcutlinbosub3subwaveguides AT andreikozlov applicabilityoftheeffectiveindexmethodforthesimulationofxcutlinbosub3subwaveguides AT ulianasalgaeva applicabilityoftheeffectiveindexmethodforthesimulationofxcutlinbosub3subwaveguides AT victorkrishtop applicabilityoftheeffectiveindexmethodforthesimulationofxcutlinbosub3subwaveguides AT anatoliivolyntsev applicabilityoftheeffectiveindexmethodforthesimulationofxcutlinbosub3subwaveguides |