An example device includes a nanovoided polymer element, which may be located at least in part between the electrodes. In some examples, the nanovoided polymer element may include anisotropic voids, including a gas, and separated from each other by polymer walls. The device may be an electroactive device, such as an actuator having a response time for a transition between actuation states. The gas may have a characteristic diffusion time (e.g., to diffuse half the mean wall thickness through the polymer walls) that is less than the response time. The nanovoids may be sufficiently small (e.g., below 1 micron in diameter or an analogous dimension), and/or the polymer walls may be sufficiently thin, such that the gas interchange between gas in the voids and gas absorbed by the polymer walls may occur faster than the response time, and in some examples, effectively instantaneously.

A mobile system includes a self-supporting platform, a tunable reflective skin or film disposed on and secured to the mobile platform, one or more actuators and a controller. The tunable reflective skin or film includes one or more layers that are at least partially reflective to optical energy at one or more optical wavelengths. The skin or film is substantially flexible and/or stretchable and has an optical reflectivity to incident electromagnetic radiation of a given wavelength which is selectively variable when flexed and/or stretched. The actuators are able to flex and/or stretch the skin or film in response to receipt of a control signal. The controller generates the control signal based on a measured value of the optical reflectivity of the skin or film to the incident electromagnetic radiation of the given wavelength.

Example methods include depositing a precursor layer onto a substrate where the precursor layer includes droplets comprising a polymerizable material, inducing a phase inversion in the precursor layer to obtain a modified precursor layer including droplets of a non-polymerizable liquid within a polymerizable liquid mixture, and polymerizing the polymerizable liquid mixture to obtain a nanovoided polymer element. Examples include devices fabricated using nanovoided polymer elements fabricated using such methods, including electroactive devices such as actuators and sensors.

An optical element includes a nanovoided polymer layer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Compression or expansion of the nanovoided polymer layer, for instance, can be used to reversibly control the size and shape of the nanovoids within the polymer layer and hence tune its refractive index over a range of values, e.g., during operation of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.

A display device includes a scanned projector for projecting a beam of light, and a diffraction grating for dispersing the light at a plurality of angles into a waveguide, wherein at least a portion of the diffraction grating includes a nanovoided polymer. Manipulation of the nanovoid topology, such as through capacitive actuation, can be used to reversibly control the effective refractive index of the nanovoided polymer and hence the grating efficiency. The switchable grating can be used to control the amount of diffraction of an incident beam of light through the grating thereby decreasing optical loss. Various other methods, systems, apparatuses, and materials are also disclosed.

In some examples, a device includes a nanovoided polymer element, a planarization layer disposed on a surface of the nanovoided polymer element, a first electrode disposed on the planarization layer, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. The planarization layer may be located between the nanovoided polymer element and the first electrode.

Systems and methods for optical computation and acousto-optic modulation are described. The systems and methods comprise acousto-optic modulators with reflectors and transducers used for actuation and modulation of mechanical waves. The systems further comprise multilayer optical computing systems incorporating arrays of acousto-optic modulators. In an embodiment, the acousto-optic modulator comprises a substrate; an optical layer coupled to a first portion of the substrate, the optical layer comprising: a free-standing portion shaped and positioned to define a gap between the free-standing portion of the optical layer and the substrate; and a rib waveguide comprising a photonic crystal, formed in the free-standing portion; and a piezoelectric transducer mechanically coupled to the free-standing portion, wherein the piezoelectric transducer comprises a piezoelectric material and a plurality of conductive electrodes disposed in electrically conductive contact with the piezoelectric material, the plurality of conductive electrodes extending from a base portion of the piezoelectric transducer.

The present disclosure relates to use of a quaternary molybdenum/tungsten tellurite crystal and a device thereof. The quaternary molybdenum/tungsten tellurite crystal is used as an acousto-optic material, wherein the quaternary molybdenum/tungsten tellurite comprises tellurium (Te) and tungsten (W), or tellurium (Te) and molybdenum (Mo). The crystal has abundant kinds, is non-toxic, and includes high, medium and low symmetry crystal systems; it easily produces a large-size and high-quality single crystal and almost meets all requirements of excellent acousto-optic properties. In the present disclosure, by selecting different light transmission directions and excitation source directions to fabricate an acousto-optic device with practical application values according to the requirements of the crystal acousto-optic device and the crystal characteristics, high-performance acousto-optic Q switching laser output is achieved.

An example device includes a nanovoided polymer element, a first electrode, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. In some examples, the nanovoided polymer element may include anisotropic voids. In some examples, anisotropic voids may be elongated along one or more directions. In some examples, the anisotropic voids are configured so that a polymer wall thickness between neighboring voids is generally uniform. Example devices may include a spatially addressable electroactive device, such as an actuator or a sensor, and/or may include an optical element. A nanovoided polymer layer may include one or more polymer components, such as an electroactive polymer.

A form birefringent optical element includes a structured layer and a dielectric environment disposed over the structured layer. At least one of the structured layer and the dielectric environment includes a nanovoided polymer, the nanovoided polymer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Actuation of the nanovoided polymer can be used to reversibly control the form birefringence of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.