Structural and Optical Properties of Crystal Ion Sliced BaTiO$_3$ Thin Films

Hossein Esfandiar; Fatemeh Abtahi; Trevor G. Vrckovnik; G. Quyet Ngo; Rene Heller; Ulrich Kentsch; Fabian Ganss; Stefan Facsko; Uta Lucchesi; Stephan Winnerl; Falk Eilenberger; Dennis Arslan; Sebastian W. Schmitt

arXiv · 2508.05874

Structural and Optical Properties of Crystal Ion Sliced BaTiO$_3$ Thin Films

Hossein Esfandiar·Fatemeh Abtahi·Trevor G. Vrckovnik·G. Quyet Ngo·Rene Heller·Ulrich Kentsch·Fabian Ganss·Stefan Facsko·Uta Lucchesi·Stephan Winnerl·Falk Eilenberger·Dennis Arslan·Sebastian W. Schmitt

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Abstract

Barium titanate (BaTiO$_3$) is a compelling material for integrated photonics due to its strong electro-optic and second-order nonlinear properties. Crystal Ion Slicing (CIS) presents a scalable and CMOS-compatible route for fabricating thin BaTiO$_3$ films; however, ion implantation during CIS introduces lattice damage that can degrade structural and optical performance. In this study, we demonstrate that post-slicing thermal annealing effectively restores the structural integrity and optical quality of CIS-processed BaTiO$_3$ flakes. Raman spectroscopy confirms the recovery of crystallinity, while second-harmonic generation (SHG) microscopy reveals systematic reorientation of ferroelectric domains and restoration of the associated second-order nonlinear susceptibility tensor $X^{(2)}$. Notably, SHG signals persist even in regions with weak Raman signatures, indicating that long-range ferroelectric order can survive despite partial lattice disruption. Optical measurements show that the linear dispersion of annealed CIS flakes closely matches that of bulk BaTiO$_3$, validating their suitability for photonic integration. Together, these results qualify CIS - combined with thermal annealing - as a viable and scalable manufacturing strategy for high-quality BaTiO$_3$-on-insulator (BTOI) platforms, enabling advanced integrated photonic devices for modulation, frequency conversion, and quantum optics.

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Hossein Esfandiar, Fatemeh Abtahi, Trevor G. Vrckovnik, G. Quyet Ngo, Rene Heller, Ulrich Kentsch, Fabian Ganss, Stefan Facsko, Uta Lucchesi, Stephan Winnerl, Falk Eilenberger, Dennis Arslan, Sebastian W. Schmitt. 2025-08-07. Structural and Optical Properties of Crystal Ion Sliced BaTiO$_3$ Thin Films. https://arxiv.org/abs/2508.05874

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