Lead-Free Perovskite Thin Films with Tailored Pockels-Kerr Effects for Photonics

Area of Science:

• Materials Science
• Photonics
• Quantum Computing

Background:

• Pockels and Kerr effects are linear and nonlinear electro-optical phenomena, respectively.
• Refractive index modulation is key for photonic circuits, but room-temperature quantum computing demands stronger effects.
• High Pockels/Kerr effects and nonlinear susceptibilities (χ(2)/χ(3)) are needed for advanced photonic elements.

Purpose of the Study:

• To demonstrate composition-modulated strong electro-optical response in epitaxial (Ba,Ca)(Ti,Zr)O3 perovskite titanate films.
• To investigate the relationship between film composition and electro-optical properties.
• To explore the potential of these materials for integrated nonlinear optical elements.

Main Methods:

• Epitaxial growth of (Ba,Ca)(Ti,Zr)O3 films using pulsed laser deposition on SrTiO3 substrates.
• Tuning the Ca/Ba and Ti/Zr ratios to control film composition.
• Characterization of Pockels and Kerr optical nonlinearities.

Main Results:

• Demonstrated tunable, strong electro-optical response in (Ba,Ca)(Ti,Zr)O3 films.
• Achieved high Pockels or Kerr optical nonlinearities by adjusting Ca/Ba and Ti/Zr ratios.
• Linked the variable electro-optic response to nanopolar domains with differing symmetries.

Conclusions:

• Composition modulation in (Ba,Ca)(Ti,Zr)O3 films enables strong, tunable electro-optical effects.
• These materials are promising for developing nonlinear optical elements for integrated photonic circuits.
• The findings facilitate the implementation of photonic elements for room-temperature quantum computing.