High-frequency cavity optomechanics using bulk acoustic phonons

Abstract

To date, microscale and nanoscale optomechanical systems have enabled many proof-of-principle quantum operations through access to high-frequency (gigahertz) phonon modes that are readily cooled to their thermal ground state. However, minuscule amounts of absorbed light produce excessive heating that can jeopardize robust ground-state operation within these microstructures. In contrast, we demonstrate an alternative strategy for accessing high-frequency (13 GHz) phonons within macroscopic systems (centimeter scale) using phase-matched Brillouin interactions between two distinct optical cavity modes. Counterintuitively, we show that these macroscopic systems, with motional masses that are 1 million to 100 million times larger than those of microscale counterparts, offer a complementary path toward robust ground-state operation. We perform both optomechanically induced amplification/transparency measurements and demonstrate parametric instability of bulk phonon modes. This is an important step toward using these beam splitter and two-mode squeezing interactions within bulk acoustic systems for applications ranging from quantum memories and microwave-to-optical conversion to high-power laser oscillators.

Polariton-driven phonon laser

“…1b, P Pump = 2.3 P Th ), the polariton BEC is evidenced by the narrowing and concentration of the emission at the bottom of the trap, as well as by the blueshift of the states induced by polariton-polariton interactions mediated by their excitonic component, as well as polariton interactions with the excitonic reservoir 17 . Figure 1c-f summarize the results of a two-laser OMIA experiment 27 , performed on this 40-μm-wide stripe. The first (pump) laser creates a BEC in the stripe.…”

Hybrid integrated photonics using bulk acoustic resonators

“…Based on these observations and the fact that the acoustic impedance of SiO 2 is smaller than Si and then AlN, we can conclude that, for two coupled acoustic cavities, the small cavity (e.g., SiO 2 ) with smaller acoustic impedance tends to decrease (increase) the effective cavity length (FSR) of the big cavity (e.g., Si) when it's on resonance compared with off-resonance and vice versa 38 . This is similar to coupled optical cavities by treating acoustic impedance as the effective refractive index 39 .…”

“…The roll-off starting around 3.5 GHz is caused by reduced FSR due to coupling of the AlN cavity. This study of mechanical dispersion could benefit the growing field of mechanical dispersion engineering for future applications (e.g., mechanical dissipative solitons 40,41 , HBAR-based quantum random access memory 39,42 ) and future devices improvement by optimizing Si, SiO 2 , and AlN thicknesses or by choosing materials with different acoustic impedance. In this sense, further theoretical and numerical studies are necessary for a more complete understanding of the acoustic wave propagation and mechanical cavity coupling in such a platform.…”

Optomechanically Induced Birefringence and Optomechanically Induced Faraday Effect

“…consisting of a high-Q planar Fabry-Pérot resonator with a movable mirror, as is used in many experiments (see Fig. 1) [34,[36][37][38][39][40][41][42][43][44][45]. This system naturally hosts degenerate modes of orthogonal polarization that are both coupled to a mechanical resonator mode, while similar concepts, however, may be envisioned in a broad class of 2D and 3D geometries.…”