Directional couplers and multimode interferometers at room and helium temperatures

Lebedeva E.S., Venediktov I.O., Korovin V.A., Kobtsev D.M., Golikov A.D., An P.P., Kovalyuk V.V., Goltsman, G.N.

For Russian citation (Opticheskii Zhurnal):

Лебедева Е.С., Венедиктов И.О., Коровин В.А., Кобцев Д.М., Голиков А.Д., Ан П.П., Ковалюк В.В., Гольцман Г.Н. Направленные ответвители и мультимодовые интерферометры при комнатной и гелиевой температурах // Оптический журнал. 2026. Т. 93. № 5. С. 71–81. http://doi.org/10.17586/1023-5086-2026-93-05-71-81

Lebedeva E.S., Venediktov I.O., Korovin V.A., Kobtsev D.M., Golikov A.D., An P.P., Kovalyuk V.V., Goltsman G.N. Directional couplers and multimode interferometers at room and helium temperatures [in Russian] // Opticheskii Zhurnal. 2026. V. 93. № 5. P. 71–81. http://doi.org/10.17586/1023-5086-2026-93-05-71-81

For citation (Journal of Optical Technology):

Abstract:

Subject of the study. Dependences of the division ratio of integrated optical splitters in the form of a directional responder and a multimode interferometer on the geometric parameters at room and cryogenic temperatures. The aim of the work is to experimentally study the manifestation of the dependence of the division ratio of integrated optical splitters on the silicon nitride platform on the geometric parameters depending on the wavelength from 1.47 to 1.64 μm at room and cryogenic temperatures for further application in quantum computing. Method. Fabrication of samples with structures changing the geometric parameters by the electron lithography method and further experimental study of the reflection at wavelengths of 1.47–1.64 μm at room and cryogenic temperatures. Main results. Based on experimental data, the dependences of the division ratio on the geometric parameters of integrated optical splitters on a silicon nitride substrate were calculated and plotted. It was revealed that, depending on this, they are periodic in nature. When cooling multimode interferometers to 5 K, changes in the division ratio of approximately 28% were recorded compared to values obtained at 300 K. Compared to directional couplers (30.2%), this is less typical for the design of quantum-optical microcircuits. Practical ingenuity. The data obtained can be used in the future to create highly efficient components for quantum computers, as well as to design on-chip radio- and nanophotonic circuits operating at various temperatures.

Keywords:

integrated optical splitters, directional couplers, multimode interferometers, division ratio, extinction ratio

Acknowledgements:

this work was supported by the Russian Science Foundation Grant № 23-12-00187 (development of equipment for measurements at helium temperatures) and the Ministry of Science and Higher Education (FSME-2025-0002)

OCIS codes: 130.0130, 130.1750, 130.6750

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