Fig. 1. (a) Cross section of the hybrid Si-BTO waveguide. (b) Simulated mode profile of the hybrid Si-BTO waveguide. (c) Simulated light confinement factor and effective index as a function of the thickness of the silicon layer. (d). Simulated light confinement factor and effective index as a function of the thickness of BTO thin film. (e) Simulated light confinement factor and effective index as a function of the width of the silicon layer.

Fig. 2. (a) 3D schematic diagram of hybrid Si-BTO racetrack resonator. (b) Simulated cross-sectional static electric field distribution of hybrid Si-BTO racetrack resonator. (c) Simulated average electric field as a function of electrode gaps. (d) Simulated EO overlap factor as a function of the thicknesses of silicon layers and BTO films.

Fig. 3. (a) Fabrication process of the hybrid Si-BTO devices using the CSD method. (b) SEM photo of the surface of the BTO thin film. (c) SEM photo of the cross section of the Si-BTO waveguide region. (d) AFM on the surface of the BTO thin film. (e) Measured surface roughness across different areas. (f) XRD spectrum of the deposited BTO thin film.

Fig. 4. (a) Measured transmission spectrum of the silicon racetrack resonator. (b) Lorentz fitting of a resonance dip of the silicon racetrack resonator. (c) Measured transmission spectrum of the hybrid Si-BTO racetrack resonator. (d) Lorentz fitting of a resonance dip of the hybrid Si-BTO racetrack resonator.

Fig. 5. (a) Measured transmission spectra when applying different voltages. (b) Linear fitting of the resonance wavelengths as a function of the applied voltages. (c) Measured I-V hysteresis curve of the fabricated racetrack resonators. (d) Power consumption as a function of resonance wavelength shift.

Fig. 6. (a) Experimental setup for high-speed test. EDFA, erbium-doped optical fiber amplifier; PC, polarization controller; EA, electric amplifier; DUT, device under test; PD, photodetector; DSO, digital storage oscilloscope. (b) Measured eye diagrams of NRZ signals at 30, 40, and 50 Gbps. (c) BER as a function of the received optical power.

Table 1. Comparison between different deposition methods of BTO film.

Table 2. Performance comparison of the integrated tuning devices.