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arXiv · 2402.15203

Polarization splitter rotator on thin film lithium niobate based on multimode interference

Mengke Wang·Hao Yao·Jiayao Deng·Zhefeng Hu·Tingting Tang·Kaixin Chen
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Abstract

Polarization splitter-rotators (PSRs) are the key elements to realize on-chip polarization manipulation. Current PSRs on thin film lithium niobate (TFLN) rely on sub-micron gaps to realize modes separation, which increase the difficulties of lithography and etching. In this paper, a polarization splitter-rotator on TFLN based on multimode interference (MMI) is demonstrated. Mode division is achieved by an MMI-based mode demultiplexer. The feature size of the PSR is 1.5 {\mu}m, which can be fabricated with low priced i-line contact aligners. Experimental results show a polarization extinction ratio (PER) > 20 dB and insertion loss (IL) <1.5 dB are achieved in a wavelength range of 1542-1600 nm for TE-polarized light. And a PER > 9.5 dB and an IL <3.0 dB are achieved in a wavelength range of 1561-1600 nm for TM-polarized light. This PSR could find application in the low-cost fabrication of dual-polarization TFLN integrated photonic devices.

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Mengke Wang, Hao Yao, Jiayao Deng, Zhefeng Hu, Tingting Tang, Kaixin Chen. 2024-02-23. Polarization splitter rotator on thin film lithium niobate based on multimode interference. https://arxiv.org/abs/2402.15203

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