Abstract
Mid-infrared electro-optic (EO) modulation
efficiency and high-frequency performance of barium titanate (BTO)
modulators on a germanium-on-silicon platform are investigated.
Leveraging its exceptional Pockels coefficients, BTO exhibits
remarkable EO modulation capabilities in both transverse-electric (TE)
mode for a-axis growth and transverse-magnetic (TM) mode for c-axis
growth. At the wavelength of 3.8 µm, the V
π
⋅L for a-axis oriented BTO (TE
polarization) is 1.90 V·cm, and for c-axis oriented BTO (TM
polarization), it is 2.32 V·cm, which have better performance
than those of the Pockels effect based EO modulators from literature.
In addition, the high-frequency EO response of the modulator is
simulated, and a 3-dB EO bandwidth of 62.82 GHz with the
optimized traveling wave electrodes is achieved, showing promise in
the high-speed MIR applications such as free-space optical
communications.
Funder
Shanghai Collaborative Innovation Center of Intelligent Sensing Chip Technology
National Natural Science Foundation of China
Shanghai Key Laboratory of Chips and Systems for Intelligent Connected Vehicle
Shanghai Technical Service Computing Center of Science and Engineering, Shanghai University