P. V. Volkov, O. S. Vyazankin, A. I. Bobrov, A. V. Nezhdanov, D. A. Semikov, K. V. Sidorenko, “Study of the low-order mode field structure impact on <nobr>$Y$</nobr>-splitter parameters in photonic integrated circuits”, Pisma v Zhurnal Tekhnicheskoi Fiziki, 2025, Volume 51, Issue 19,Pages <nobr>19

Study of the low-order mode field structure impact on $Y$-splitter parameters in photonic integrated circuits

P. V. Volkov^a, O. S. Vyazankin^a, A. I. Bobrov^b, A. V. Nezhdanov^b, D. A. Semikov^a, K. V. Sidorenko^b

^a Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhnii Novgorod
^b Lobachevsky State University of Nizhny Novgorod

Abstract: The impact of low-order mode operation in silicon integrated waveguides on the performance of $Y$-splitters with a rib geometry, fabricated on a silicon-on-insulator (SOI) platform, is investigated. It is demonstrated that the TE$_{10}$ mode, emerging when a standard 500 $\times$ 220 nm channel silicon waveguide is overgrown with silicon oxide, significantly alters the $Y$-splitter characteristics. As a result, the splitting ratio becomes dependent on the relative alignment between the optical fiber delivering light to the photonic integrated circuit and the input coupling structure.

Keywords: rib waveguides, channel waveguides, integrated splitters.

Received: 21.01.2025
Revised: 02.07.2025
Accepted: 04.07.2025

DOI: 10.61011/PJTF.2025.19.61145.20261