Search

A massive phonon mode in a high-overtone bulk acoustic wave resonator has been laser cooled close to its ground state. Its robustness to decoherence establishes the potential of these devices for quantum technologies.

Self-injection locking of an on-chip laser to a milimetre-scale vacuum-gap Fabry–Pérot cavity is demonstrated, with a phase noise of –97 dBc Hz^–1 at a 10-kHz offset frequency and a fractional frequency stability of 5 × 10⁻¹³ at 10 ms, enabling next-generation high-performance integrated systems.

Researchers demonstrated integrated non-magnetic isolators with 24.5-dB contrast, –2.16-dB insertion loss and 2-THz (16-nm) optical bandwidth.

Integrated photonics hold potential for signal processing but some operations are difficult to perform in all-optical devices. Here, Shin et al. use the coupling between coherent photons and phonons in nanophotonic waveguides to demonstrate frequency-selective, narrow-linewidth radiofrequency photonic filters.

Exploiting photon–phonon coupling in nanoscale silicon waveguides could enable a host of powerful features in photonic devices. Using a hybrid photonic–phononic waveguide structure, Shin et al. show stimulated Brillouin scattering nonlinearities and gain, which offers new on-chip signal-processing abilities.

The authors showcase an optical-to-microwave conversion method using an optomechanical waveguide integrated with a piezoelectric transducer. The presented system allows bidirectional optical-to-microwave conversion with a quantum efficiency of up to—54.16 dB.

Self-oscillation and shuttling of photons between distinct cavities in a photonic see-saw provide unexpected opportunities in nano-optomechanics.

Here the authors developed on-chip microresonators with a remarkable Q-factor of 38 million and demonstrated on-chip Brillouin lasing in the mid-infrared. These results highlight opportunities to create more compact and efficient platforms for molecular science.

Here, Kittlauset al. demonstrate stimulated inter-modal Brillouin scattering on-chip. Through this process, a Brillouin interaction couples light fields that propagate in distinct spatial modes of a Brillouin-active silicon waveguide, which may allow a variety of new processes in silicon photonics.

Net Brillouin amplification is demonstrated in silicon with just 5 mW pumping. Greater than 5 dB amplification is achieved.

It remains challenging to realize narrowband filters needed for high-performance communications systems using integrated photonics. Using a multi-port Brillouin-based optomechanical system, the authors demonstrate an ultra-narrowband notch filter with high rejection with CMOS compatible techniques.

Non-reciprocal single-sideband modulation and mode conversion are realized in a low-loss integrated silicon waveguide, enabling >125 GHz operation bandwidths and up to 38 dB of non-reciprocal contrast between forward- and backward-propagating waves.

Circuit quantum acoustodynamics is used to achieve controlled generation of multi-phonon Fock states in a bulk acoustic-wave resonator, which are demonstrated to have a quantum nature.

Acoustically opaque glass can regain its transparency through coherently driven fields. Combining experiments and theory, the phononic saturation process is presented as analogous to the spectral hole burning process.

Optomechanical coupling to macroscopic phonon modes of a bulk acoustic-wave resonator is demonstrated, providing access to high acoustics quality factors for phononic modes at high frequencies that are robust to decoherence.

The electro-acoustic effect can be used to electrically control the phase velocity of travelling acoustic waves in a lithium niobate waveguide, and to construct devices that can modulate the phase, frequency and amplitude of acoustic waves, even at the limit of single phonons.

We leverage advances in integrated photonics to generate low-noise microwaves with an optical frequency division architecture that can be low power and chip integrated.

In this work the authors demonstrate on-chip integration of Brillouin lasing operating at visible wavelengths, with engineered design for stable output. This technical and scientific advance will help develop integrated light sources for quantum computing or atomic and molecular spectroscopy.

Integrated photonic all-waveguide resonators are a critical component in many future applications. Here the authors develop an optimized photonic all-waveguide resonator with an ultra-high quality factor, Q, of almost half a billion, and a narrow sub-MHz linewidth.

Cold-atom interferometers have been miniaturized towards fieldable quantum inertial sensing applications. Here the authors demonstrate a compact cold-atom interferometer using microfabricated gratings and discuss the possible use of photonic integrated circuits for laser systems.

Direct acousto-optic modulation within complementary metal–oxide–semiconductor compatible silicon photonic waveguides using electrically driven surface acoustic waves is demonstrated. Non-reciprocal operation bandwidths of >100 GHz and insertion losses of <0.6 dB are obtained.

Brillouin lasing with 0.7 Hz fundamental linewidth is observed by optically exciting a monolithic bus–ring Si₃N₄ waveguide resonator. The Brillouin laser is applied to an optical gyroscope and a low phase-noise photonic microwave oscillator.

Acousto-optical interactions within integrated optics platforms are reviewed with a discussion of the useful chip-based devices such as lasers, amplifiers, filters, isolators and more besides that can result.