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arXiv · 2507.17150

Low loss monolithic barium titanate on insulator integrated photonics with intrinsic quality factor >1 million

Gwan In Kim·Jieun Yim·Gaurav Bahl
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Abstract

Barium titanate (BTO) has been experiencing a surge of interest for integrated photonics technologies because of its large nonlinear optical coefficients, especially the Pockels coefficient, and in part due to newly available thin-film substrates. In this work, we report on the development of a redeposition-free dry etching technique for monolithic BTO-on-insulator photonics, that produces very low-roughness and high-verticality waveguides. Using this, we experimentally demonstrate the first BTO microresonators with intrinsic Q-factor $> 1$ million, and waveguide propagation loss as small as 0.32 dB/cm, representing the lowest losses reported in any BTO-based integrated platform to date. We additionally demonstrate Mach-Zehnder amplitude modulators with $V_{\pi}L = 0.54$ V$\cdot$cm and effective electro-optic coefficient $r_\text{eff} = 162$ pm/V.

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Gwan In Kim, Jieun Yim, Gaurav Bahl. 2025-07-23. Low loss monolithic barium titanate on insulator integrated photonics with intrinsic quality factor >1 million. https://arxiv.org/abs/2507.17150

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