Laser localization paper appears in PRA!

Laser-defined mechanical mode of a photonic crystal membrane.
Laser-defined mechanical mode of a photonic crystal membrane.

In the field of optomechanics, the forces exerted by light have provided a particularly high level of control over the frequency and dissipation of mechanical systems at all size scales. Here we propose a new class of optomechanical systems in which light exerts a similarly profound influence over the two remaining fundamental parameters: geometry and mass. Specifically, we show that by optically levitating one lattice site of an extended mechanical crystal (image), it is possible to control the shape and spatial extent of a mechanical mode. Furthermore, owing to light’s simultaneous and constructive effect on structure’s continuum of modes, we estimate that laser light at the level of a single photon should be capable of producing a measurable effect within a realistic, chip-scale device.

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Two-mode noise interference paper on the arxiv!

Aash-paper-1
“Trampoline-in-the-middle” (TIM) system.

Here we (Yariv) analyze(s) a system in which the coupling between two optical modes is modulated by the motion of a mechanical element. Interestingly, we find that this class of systems should be capable of ground state cooling in the so-called “bad cavity” limit, due to interference of quantum noise (a more general instance of “dissipative coupling”). Also, contrary to a common intuition, we show that quantum nondemolition readout is in general not possible in this class of systems without single-photon strong optomechanical coupling.

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Trampoline paper appears in PRX!

Complicated2

Force measurements and optomechanics experiments typically call for lightweight, low-noise, and optically pristine mechanical elements. We have created delicate, nanogram-scale “trampoline” mechanical sensors that achieve a record 16 attonewton force sensitivity at room temperature (equivalent to the gravitational pull between two people 100 kilometers apart). These trampolines are furthermore compatible with the high-quality optical elements required for optomechanics experiments, in principle enabling laser light at the level of a single photon to strongly influence their mechanical trajectories.

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Physics Viewpoint: Trampolines Sense a Disturbance in the Force

Laser localization proposal on the arxiv!

Laser-defined mechanical mode of a photonic crystal membrane.
Laser-defined mechanical mode of a photonic crystal membrane.

In the field of optomechanics, the forces exerted by light have provided a particularly high level of control over the frequency and dissipation of mechanical systems at all size scales. Here we propose a new class of optomechanical systems in which light exerts a similarly profound influence over the two remaining fundamental parameters: geometry and mass. Specifically, we show that by optically levitating one lattice site of an extended mechanical crystal (image), it is possible to control the shape and spatial extent of a mechanical mode. Furthermore, owing to light’s simultaneous and constructive effect on structure’s continuum of modes, we estimate that a trap intensity at the level of a single photon should be capable of producing a measurable effect within a realistic, chip-scale device.

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Trampoline paper on the arxiv!

High-aspect-ratio "trampoline" resonator: 100-nanometer-thick, 100-micron-diameter "pad" supported by 2-micron-wide, 2-millimeter-long tethers.
High-aspect-ratio “trampoline” resonator: 100-nanometer-thick, 100-micron-diameter “pad” supported by 2-micron-wide, 2-millimeter-long tethers.

We have fabricated delicate, nanogram-scale “trampoline” mechanical sensors that, when struck, ring for more than 5 minutes. As a result, these devices are exquisitely sensitive to tiny forces (of order attonewtons) at room temperature. Fabricated with standard “top-down” techniques, they are compatible with a wide variety of probes or other on-chip systems, making them well-suited for many integrated force sensing applications. We furthermore demonstrate compatibility with high-finesse optics for sensitive readout and optomechanics experiments, and the unprecedented combination of mechanical and optical performance implies that the radiation forces exerted by laser light at the level of a single photon will profoundly influence their motion. It should even be possible to observe evidence of energy quantization in their driven mechanical oscillations.

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Fiber cavity paper on the arxiv!

Fiber Cavity Diamond

An important tool for both optomechanics and quantum optics is an optical cavity, which can be used to resonantly enhance the interaction between light and whatever object is positioned within. In order to interact with incredibly small objects, it is beneficial to create a cavity with a very small mode volume.

In collaboration with the Childress Group at McGill, we report our first successful fabrication of a high-finesse fiber-based Fabry-Perot optical cavity, and explore how it is affected by a thick (~10 micron) slab of single-crystal diamond. Importantly, we find that the cavity still performs quite well (finesse of 17,000) with the diamond inside, and that the bulk of the diamond does not impact performance as much as the surface. For the field of nitrogen-vacancy (NV) photonics, this means one can simultaneously benefit from the long coherence times of NV defects far from surfaces, a high Purcell enhancement, and a tunable, narrow-linewidth optical resonator. For the field of optomechanics, this builds our confidence that we can create wavelength-scale opomechanical systems with the Fabry-Perot geometry. Thanks for being the guinea pig, Lily!

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