

Dependence of Optical Losses on the Thickness of the Buffer Layer Between a Thin-film Lithium Niobate Waveguide and a Metal Electrode
https://doi.org/10.17586/0021-3454-2025-68-4-310-319
Abstract
The optical losses in the intersection region of a gold electrode and a thin-film lithium niobate optical waveguide are investigated. It is possible to reduce the absorption of optical radiation in the waveguide by selecting the buffer layer thickness. Using the finite element method and the Mueller and Newton–Raphson numerical methods, the dependence of the optical losses in the waveguide on the buffer layer thickness is determined. It is shown that when the buffer layer thickness changes from zero to one micrometer, the optical losses in the intersection region of the waveguide and the electrode decrease from 6·102 to 10–3 dB/cm for the fundamental TM mode and from 102 to 10–3 dB/cm for the fundamental TE mode. The correctness of the calculation is confirmed by the consistency of the data obtained by three different methods. The results can be used in designing functional elements of photonic integrated circuits (phase, amplitude modulators, etc.) with minimal optical losses due to absorption of gold electrodes.
Keywords
About the Authors
A. V. BulatovaRussian Federation
Anna V. Bulatova — Post-Graduate Student Department of General Physics; research engineer
Perm
D. N. Moskalev
Russian Federation
Dmitriy N. Moscalev — M. Sc. Department of Nanotechnologies and Microsystem Technique; assistant, Department of General Physics; researcher; lead research engineer
Perm
U. O. Salgaeva
Russian Federation
Ulyana O. Salgaeva — PhD expert
Moscow
V. A. Maksimenko
Russian Federation
Vitaly A. Maksimenko — PhD, Associate Professor Department of General Physics
Perm
V. V. Krishtop
Russian Federation
Victor V. Krishtop — Dr. Sci., Professor Department of General Physics, professor; Department of Nanotechnologies and Microsystem Technique, professor; chief scientist
Perm
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Review
For citations:
Bulatova A.V., Moskalev D.N., Salgaeva U.O., Maksimenko V.A., Krishtop V.V. Dependence of Optical Losses on the Thickness of the Buffer Layer Between a Thin-film Lithium Niobate Waveguide and a Metal Electrode. Journal of Instrument Engineering. 2025;68(4):310-319. (In Russ.) https://doi.org/10.17586/0021-3454-2025-68-4-310-319