Optomechanical antennas for on-chip beam-steering

Abstract

Rapid and low-power control over the direction of a radiating light field is a major challenge in photonics and a key enabling technology for emerging sensors and free-space communication links. Current approaches based on bulky motorized components are limited by their high cost and power consumption, while on-chip optical phased arrays face challenges in scaling and programmability. Here, we propose a solid-state approach to beam-steering using optomechanical antennas. We combine recent progress in simultaneous control of optical and mechanical waves with remarkable advances in on-chip optical phased arrays to enable low-power and full two-dimensional beam-steering of monochromatic light. We present a design of a silicon photonic system made of photonic-phononic waveguides that achieves 44° field of view with 880 resolvable spots by sweeping the mechanical wavelength with about a milliwatt of mechanical power. Using mechanical waves as nonreciprocal, active gratings allows us to quickly reconfigure the beam direction, beam shape, and the number of beams. It also enables us to distinguish between light that we send and receive.

Controlling phonons and photons at the wavelength scale: integrated photonics meets integrated phononics

“…Phononic confinement, propagation losses and lifetimes are limited by various imperfections such as geometric disorder [29,40,55,[66][67][68], thermo-elastic and Akhiezer damping [25,69], two-level systems [70][71][72] and clamping losses [14,73,74]. Losses in 2D-confined waveguides are typically quantified by a propagation length L m = α −1 m .…”

Time-of-flight imaging based on resonant photoelastic modulation

“…Scanning of the beam can be realized through mechanical [9,10] scanning or non-mechanical scanning (solid state). Non-mechanical scanning usually uses optical phased arrays with full control of the phase and frequency of a laser beam [11][12][13][14], although recently solid state optomechanical steering has also been proposed [15]. An alternative method, usually referred to as flash lidar, captures depth images through illuminating a part of the scene with a modulated light source.…”

Integrated Nonreciprocal Photonic Devices with Dynamic Modulation

“…A number of resonant acoustically-driven devices have also been theoretically proposed and experimentally demonstrated [103,[124][125][126][127][128][129]. Unlike electro-optical modulators, acousto-optic modulation schemes can be driven either optically by beating a higher power optical pump wave with a lower power detuned probe wave [103,126], or electrically via surface wave or other forms of transducers [105,128].…”