Amirmahdi Honardoost

High-performance and linear thin-film lithium niobate Mach-Zehnder modulators on silicon up to 50 GHz

Compact electro-optical modulators are demonstrated on thin films of lithium niobate on silicon operating up to 50 GHz. The half-wave voltage length product of the high-performance devices is 3.1 V.cm at DC and less than 6.5 V.cm up to 50 GHz. The 3 dB electrical bandwidth is 33 GHz, with an 18 dB extinction ratio. The third-order intermodulation distortion spurious free dynamic range is 97.3  dBHz2/3 at 1 GHz and 92.6  dBHz2/3 at 10 GHz. The performance demonstrated by the thin-film modulators is on par with conventional lithium niobate modulators but with lower drive voltages, smaller device footprints, and potential compatibility for integration with large-scale silicon photonics.

Second-harmonic generation in periodically-poled thin film lithium niobate wafer-bonded on silicon

Second-order optical nonlinear effects (second-harmonic and sum-frequency generation) are demonstrated in the telecommunication band by periodic poling of thin films of lithium niobate wafer-bonded on silicon substrates and rib-loaded with silicon nitride channels to attain ridge waveguide with cross-sections of ~2 µm2. A nonlinear conversion of 8% is obtained with a pulsed input in 4 mm long waveguides. The choice of silicon substrate makes the platform potentially compatible with silicon photonics, and therefore may pave the path towards on-chip nonlinear and quantum-optic applications.

Electro-optic and second-order nonlinear effects in thin film lithium niobate on silicon

Our recent progress on wafer-bonded thin-film lithium niobate on silicon electro-optic modulators operating up to 50 GHz, and thin-film nonlinear optical waveguide frequency converters, based on two approaches — periodic poling and poling-free grating-assisted quasi-phase matching — will be reviewed.

High-speed modeling of thin-film lithium-niobate-on-silicon electrooptic modulators

A model is developed for frequency-dependent response of compact high-speed thin-film lithium-niobate-on-silicon electrooptic modulators. The model predicts potential for > 100 GHz modulation bandwidth.