Optomechanics of Chiral Dielectric Metasurfaces

Abstract

The coupling between electromagnetic fields and mechanical motion in micro‐ and nanostructured materials has recently produced intriguing fundamental physics, such as the observation of mesoscopic optomechanical phenomena in objects operating in the quantum regime. It is also yielding innovative device applications, for instance in the manipulation of the optical response of photonic elements. Following this concept, here it is shown that combining a nanostructured chiral metasurface with a semiconductor suspended micromembrane can open new scenarios where the mechanical motion affects the polarization state of a light beam, and vice versa. Optical characterization of the fabricated samples, assisted by theory and numerical modeling, reveals that the interaction is mediated via moving‐boundary and thermoelastic effects, triggered by intracavity photons. This work represents a first example of “Polarization Optomechanics,” which can give access to new forms of polarization nonlinearities and control. It can also lead to wide applications in fast polarimetric devices, polarization modulators, and dynamically tunable chiral state generators and detectors.

Broadband Dynamic Polarization Conversion in Optomechanical Metasurfaces

“…, and w displacement components along x, y, and z directions, respectively, while the artificial displacement has been artificially exaggerated for visualization purposes. The mode resonant frequency has been found to be 372 kHz, in good agreement with independent characterization with a Laser Doppler Vibrometer [20].…”

“…In particular, by using a chiral pattern for the metasurface definition, we show a dynamical manipulation of the output light polarization, which can be dynamically controlled along non-trivial paths on the Poincarè sphere. A detailed discussion of quantitave, single frequency polarization modulation at ∼400 kHz and, conversely, light polarimetry has been reported elsewhere [20]; in this article we show how the operation bandwidth of the device can be extended to about 1.4 MHz, exploiting the overdamping regime of the mechanical resonator at atmospheric pressure.…”

“…The largest conversion effect is found around the maximum of the cross-polarized signal reported in Figure 4. A quantitative calibration of the conversion effect, which is dynamically following non-trivial paths on the Poincaré sphere, can be obtained after a careful calibration of the system, which is out of the scope of this paper and can be found elsewhere [20].…”

High-Frequency Mechanical Excitation of a Silicon Nanostring with Piezoelectric Aluminum Nitride Layers

“…Recent years have witnessed a renaissance in the investigation of micro and nanomechanical devices, pushed by the capabilities they gain when combined to photonic and/or electronic systems. Achievements such as zepto and yoctogram mass sensing [1][2][3], acceleration sensing as low as 10 μg Hz −1/2 [4], low power, light intensity [5][6][7] and, more recently, polarization [8] fast modulation are just a few examples of the technology enabled by opto and electromechanical nanosystems [9]. Following an avenue devoted to fundamental physics, these mescoscopic devices have rightfully entered the realm of quantum mechanics, inaugurated by the milestone achievement of ground-state cooling of the motion in micrometric sized optomechanical [10] and electromechanical [11] devices.…”

Optomechanically Induced Birefringence and Optomechanically Induced Faraday Effect

“…This additional degree of control over light allows quantum and classical applications, such as wavelength conversion between two distant optical frequencies [18][19][20][21] that can feature adiabatic quantum state transfer [22,23], non-demolition measurements [24], entanglement generation [25][26][27], nonreciprocal transport and optical routing [28][29][30][31][32]. For the large part, these proposals have been so far based on manipulating the scalar properties of photons, while their vector nature has only been recently pinpointed [33][34][35].…”