A BaTiO3-Based Electro-Optic Pockels Modulator Monolithically Integrated on an Advanced Silicon Photonics Platform

To develop a new generation of high-speed photonic modulators on silicon-technology-based photonics, new materials with large Pockels coefficients have been transferred to silicon substrates. Previous approaches focus on realizing stand-alone devices on dedicated silicon substrates, incompatible with the fabrication process in silicon foundries. In this work, we demonstrate monolithic integration of electro-optic modulators based on the Pockels effect in barium titanate (BTO) thin films into the back-end-of-line of a photonic integrated circuit (PIC) platform. Molecular wafer bonding allows fully PIC-compatible integration of BTO-based devices and is, as shown, scalable to 200 mm wafers. The PIC-integrated BTO Mach–Zehnder modulators outperform conventional Si photonic modulators in modulation efficiency, losses, and static tuning power. The devices show excellent VπL (0.2 Vcm) and VπLα (1.3 VdB), work at high speed (25 Gbps), and can be tuned at low-static power consumption (100 nW). Our concept demonstrates the possibility of monolithic integration of Pockels-based electro-optic modulators in advanced silicon photonic platforms.

[1]  D. Knoll,et al.  High-performance photonic BiCMOS process for the fabrication of high-bandwidth electronic-photonic integrated circuits , 2015, 2015 IEEE International Electron Devices Meeting (IEDM).

[2]  K. Neyts,et al.  Nanophotonic Pockels modulators on a silicon nitride platform , 2018, Nature Communications.

[3]  Sasan Fathpour,et al.  Heterogeneous lithium niobate photonics on silicon substrates. , 2013, Optics express.

[4]  David E. Zelmon,et al.  Molecular beam epitaxy growth of epitaxial barium silicide, barium oxide, and barium titanate on silicon , 1991 .

[5]  Wolfgang Freude,et al.  Femtojoule electro-optic modulation using a silicon–organic hybrid device , 2015, Light: Science & Applications.

[6]  P. Verheyen,et al.  Comparison of heater architectures for thermal control of silicon photonic circuits , 2013, 10th International Conference on Group IV Photonics.

[7]  S. Abel.  Electro-optic photonic devices based on epitaxial barium titanate thin films on silicon , 2014 .

[8]  Juerg Leuthold,et al.  Large Pockels effect in micro- and nanostructured barium titanate integrated on silicon , 2018, Nature Materials.

[9]  M. Webster,et al.  Low-power MOS-capacitor based silicon photonic modulators and CMOS drivers , 2015, 2015 Optical Fiber Communications Conference and Exhibition (OFC).

[10]  Andrzej Gajda,et al.  Analysis of Optical and Electrical Tradeoffs of Traveling-Wave Depletion-Type Si Mach–Zehnder Modulators for High-Speed Operation , 2015, IEEE Journal of Selected Topics in Quantum Electronics.

[11]  G. Winzer,et al.  A novel 25 Gbps electro-optic Pockels modulator integrated on an advanced Si photonic platform , 2017, 2017 IEEE International Electron Devices Meeting (IEDM).

[12]  L. Zimmermann,et al.  Record High Pockels Coefficient in PIC-Compatible BaTiO3/Si Photonic Devices , 2018, 2018 European Conference on Optical Communication (ECOC).

[13]  Lukas Czornomaz,et al.  A Hybrid Barium Titanate–Silicon Photonics Platform for Ultraefficient Electro-Optic Tuning , 2016, Journal of Lightwave Technology.

[14]  Xiaoguang Li,et al.  Ferroelectric domain switching dynamics and memristive behaviors in BiFeO3-based magnetoelectric heterojunctions , 2018 .

[15]  Lukas Czornomaz,et al.  Towards large size substrates for III-V co-integration made by direct wafer bonding on Si , 2014 .

[16]  P. Sanchis,et al.  Influence of BaTiO3 ferroelectric orientation for electro-optic modulation on silicon. , 2015, Optics express.

[17]  David J. Thomson,et al.  Silicon optical modulators , 2010 .

[18]  Florian Fallegger,et al.  Low-Loss BaTiO3–Si Waveguides for Nonlinear Integrated Photonics , 2016 .

[19]  Alexei Chelnokov,et al.  A strong electro-optically active lead-free ferroelectric integrated on silicon , 2013, Nature Communications.

[20]  Bruce W Wessels,et al.  Relative dielectric constant of epitaxial BaTiO3 thin films in the GHz frequency range , 2003 .

[21]  B. Wessels,et al.  Dielectric properties of epitaxial BaTiO3 thin films , 1998 .

[22]  J. Leuthold,et al.  Plasmonic Ferroelectric Modulators , 2019, Journal of Lightwave Technology.

[23]  P. Winzer,et al.  Integrated lithium niobate electro-optic modulators operating at CMOS-compatible voltages , 2018, Nature.

[24]  Michael Hochberg,et al.  Towards fabless silicon photonics , 2010 .

[25]  Jean Fompeyrine,et al.  Multi-Level Optical Weights in Integrated Circuits , 2017, 2017 IEEE International Conference on Rebooting Computing (ICRC).

[26]  Patrik Hoffmann,et al.  Microstructure and ferroelectricity of BaTiO3 thin films on Si for integrated photonics , 2017, Nanotechnology.

[27]  M. Chagnon,et al.  Design, analysis, and transmission system performance of a 41 GHz silicon photonic modulator. , 2015, Optics express.

[28]  S Wabnitz,et al.  Second-harmonic generation in silicon waveguides strained by silicon nitride. , 2012, Nature materials.

[29]  Chi Xiong,et al.  Active silicon integrated nanophotonics: ferroelectric BaTiO₃ devices. , 2014, Nano letters.

[30]  Juerg Leuthold,et al.  Integrated ferroelectric plasmonic optical modulator , 2017, 2017 Optical Fiber Communications Conference and Exhibition (OFC).