High-order modes suppression in an integrated optical thin-film lithium niobate phase modulator

Parfenov M.V., Tronev A.V., Agruzov P.M., Il'ichev I.V., Varlamov A.V., Usikova A.A., Zadiranov Y.M., Shamrai A.V.

Publication in Journal of Optical Technology

For Russian citation (Opticheskii Zhurnal):

Парфенов М.В., Тронев А.В., Агрузов П.М., Ильичев И.В., Варламов А.В., Усикова А.А., Задиранов Ю.М., Шамрай А.В. Подавление высших мод в интегрально-оптическом фазовом модуляторе на основе тонкопленочного ниобата лития // Оптический журнал. 2024. Т. 91. № 1. С. 80–90. http://doi.org/10.17586/1023-5086-2024-91-01-80-90

Parfenov M.V., Tronev A.V., Agruzov P.M., Ilichev I.V., Varlamov A.V., Usikova A.A., Zadiranov Y.M., Shamrai A.V. High-order modes suppression in an integrated optical thin-film lithium niobate phase modulator [in Russian] // Opticheskii Zhurnal. 2024. V. 91. № 1. P. 80–90. https://doi.org/10.17586/1023-5086-2024-91-01-80-90

For citation (Journal of Optical Technology):

Mikhail V. Parfenov, Aleksandr V. Tronev, Petr M. Agruzov, Igor V. Ilichev, Andrei V. Varlamov, Anna A. Usikova, Yurii M. Zadiranov, and Aleksandr V. Shamrai, "High-order mode suppression in an integrated optical thin-film lithium niobate phase modulator," Journal of Optical Technology. 91(1), 48-54 (2024). https://doi.org/10.1364/JOT.91.000048

Abstract:

Subjects of study are differential modal damping and filtering of fundamental mode in channel optical waveguides fabricated through etching of lithium niobate thin film on silicon dioxide buffer layer. Aims of study are development of a method for high-order modes suppression in multimode channel waveguides based on thin-film lithium niobate and determination of the topology of a highly efficient integrated optical phase modulator based on thin-film lithium niobate, fabricated using contact photolithography. Method. Numerical simulation and experimental investigation of optical and electro-optical properties of an integrated optical modulator. Main results. For an integrated optical phase modulator based on a channel waveguide produced by etching thin-film lithium niobate, the influence of planar electrodes on the differential damping of high-order modes is analyzed, and the conditions for the quasi-single-mode light propagation are determined. The topology of an integrated optical phase modulator is proposed, for which the effective suppression of high-order modes and the high efficiency of electro-optical modulation are experimentally demonstrated. The achieved parameter of modulation efficiency U_pL ≈ 4 V cm is 4 times less than that of commercially available integrated optical phase modulators based on bulk lithium niobate. Practical significance. Approaches to solving the problem of fast and inexpensive production of integrated optical modulators based on thin-film lithium niobate using mass-available standard contact photolithography, which has significant limitations in resolution and alignment accuracy, are shown.

Keywords:

thin-film lithium niobate, optical modulator, modes of optical waveguides, integrated optics, modulator

Acknowledgements:

the research was funded by the Russian Science Foundation, grant № 19-19-00511.

OCIS codes: 130.2790, 130.3730, 130.3120

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