Electro-Optic Coefficient of Thin-Film Lithium Niobate up to 270 GHz

Abstract

The linear electro-optic coefficient of lithium niobate on insulator (LNOI) thin films has been characterized over a broad range of modulation frequencies from 50 MHz to 270 GHz. A coefficient of 25-30 pm/V was found.

Plasmonic Ferroelectric Modulator Monolithically Integrated on SiN for 216 GBd Data Transmission

“…A drop-off in the modulation efficiency can be observed in the range of 1-10 GHz. This drop-off potentially arises from BTO's higher electro-optical coefficient at lower frequencies and is consistent with findings in other plasmonic devices [26,46,47]. In Fig.…”

Monolithic Barium Titanate Modulators on Silicon-on-Insulator Substrates

“…A detailed schematic of the setup used for the AC modulation experiment is shown in Figure a. Note that the devices studied in this work are not designed for the ultrahigh frequency operation recently demonstrated in BTO-based modulators, , largely a result of the capacitance associated with the devices’ large-area electrodes (Supporting Information, section 3). While future work will look to investigate the ultimate limits of the monolithic BTO modulator bandwidth, here we use AC modulation to extract an effective Pockels coefficient and understand device domain poling.…”

“…31,41−43 In addition, patterning and etching of BTO are not yet well developed, and for this reason, many BTO-based photonic structures leverage a hybrid ridge waveguide architecture, where a deposited and patterned high index material serves to guide and confine the optical mode. Such an approach has resulted in remarkable performance, 29,31,39,41,42,44,45 with V π L as low as ∼0.23 V cm reported. 35,43,46 However, hybrid geometries have decreased overlap of the optical mode with the nonlinear BTO, and thus decreased the modulation efficiency (V π L).…”

“…Many such demonstrations used BTO deposited on MgO − or lanthanum aluminate (LAO) substrates, approaches that would still require heterogeneous integration with Si electronic or photonic devices. ,− In addition, patterning and etching of BTO are not yet well developed, and for this reason, many BTO-based photonic structures leverage a hybrid ridge waveguide architecture, where a deposited and patterned high index material serves to guide and confine the optical mode. Such an approach has resulted in remarkable performance, ,,,,,, with V π L as low as ∼0.23 V cm reported. ,, However, hybrid geometries have decreased overlap of the optical mode with the nonlinear BTO, and thus decreased the modulation efficiency ( V π L ). The development of monolithic BTO-based optoelectronic devices, all else being equal, offers potential gains in device efficiency and decreased fabrication complexity.…”

Nanoimprinting Solution-Derived Barium Titanate for Electro-Optic Metasurfaces

“…The tetragonal crystal structure of BTO, with a small but influential difference in lattice constants, also leads to its high electro-optic coefficient of up to 1300 pm/V for bulk BTO, which is the largest Pockels coefficient reported to date . Epitaxially grown BTO thin-films have shown reduced electro-optic coefficients with r eff = 148 pm/V, which still exceeds the widely used thin-film lithium niobate by a factor of 5. , Plasmonic electro-optic modulators with modulation speeds in the tens of GHz range were demonstrated by integrating BTO thin-films with silicon photonics . Dielectric photonic crystal waveguides made of silicon nitride on top of a BTO film have been used to create miniaturized devices with high modulation bandwidth, thanks to the photonic band gap arising from the nanostructures .…”