Epitaxial BaTiO₃ for Emergent Silicon-Integrated Optical Computing

Silicon is essentially transparent above 1300 nm and can be machined into practically any shape with extremely high precision and with minimal surface roughness. These two properties make it extremely attractive for fabricating waveguides operating at the telecom wavelength of 1550 nm, making a natural connection between the optical fiber and Si chip. Silicon photonics has many applications, including in quantum information sciences. One of the key elements of this emergent technology is the integrated electro-optical modulator (Mach Zehnder interferometer (MZI) or ring resonator). I will discuss the recent work on integrating ferroelectric BaTiO₃ (BTO) with Si photonics to make integrated electro-optical modulators using the linear electro optic or Pockels effect for applications in optical computing [1-3].<br/>[1] W. Guo, et al., “The Epitaxial Integration of BaTiO₃ on Si for Electro-Optic Applications,” J. of Vac. Sci. Technol. A <b>39</b>, 030804 (2021).<br/>[2] A. A. Demkov et al., “Materials for emergent silicon-integrated optical computing,” J. Appl. Phys. <b>130</b>, 070907 (2021).<br/>[3] A. B. Posadas, et al., “Thick BaTiO₃ epitaxial films integrated on Si by RF sputtering for electro-optic modulators in Si photonics," ACS Applied Materials & Interfaces, https://doi.org/10.1021/acsami.1c14048, (2021).