III/V-on-lithium niobate amplifiers and lasers

We demonstrate electrically pumped, heterogeneously integrated lasers on thin-film lithium niobate, featuring electro-optic wavelength tunability. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

The convergence of cavity optomechanics and Brillouin scattering

Cavity optomechanics and Brillouin scattering have historically developed as separate fields of study, focused on distinct optoacoustic interaction effects, and realized in different physical platforms. These gaps are now closing rapidly, as researchers embrace the fundamental similarities between the two fields. Both fields study the three-wave mixing between electromagnetic and acoustic waves. Here, we review this convergence by showing how optoacoustic platforms increasingly blur the traditional distinctions between cavity optomechanics and Brillouin scattering. We discuss how the theoretical formalisms used by the two communities can be directly mapped between each other in both waveguides and cavities

Low-loss dispersion-engineered silicon nitride waveguides coated with a thin blanket layer

We demonstrate that coating with a thin blanket layer reduces the propagation loss of silicon nitride dispersion-engineered waveguides featuring strong optical field confinement

Optically heralded microwave photon addition

Photons with optical frequencies of a few hundred terahertz are perhaps the only way to distribute quantum information over long distances. Superconducting qubits, which are one of the most promising approaches for realizing large-scale quantum machines, operate on microwave photons at frequencies that are ~40,000 times lower. To network these quantum machines across appreciable distances, we must bridge this frequency gap. Here we implement and demonstrate a transducer that can generate correlated optical and microwave photons. We use it to show that by detecting an optical photon we generate an added microwave photon with an efficiency of ~35%. Our device uses a gigahertz nanomechanical resonance as an intermediary, which efficiently couples to optical and microwave channels through strong optomechanical and piezoelectric interactions. We show continuous operation of the transducer with 5% frequency conversion efficiency, input-referred added noise of ~100, and pulsed microwave photon generation at a heralding rate of 15 Hz. Optical absorption in the device generates thermal noise of less than two microwave photons. Improvements of the system efficiencies and device performance are necessary to realize a high rate of entanglement generation between distant microwave-frequency quantum nodes, but these enhancements are within reach