Abstract: An organic field effect transistor includes a channel structure having a photoalignment layer and an organic semiconductor layer disposed directly over the photoalignment layer, where a charge carrier mobility varies along a thickness direction of the channel structure. The channel structure may define an active area between a source and a drain of the transistor and may include alternating layers of at least two photoalignment layers and at least two organic semiconductor layers. Each photoalignment layer is configured to influence an orientation of molecules within an overlying organic semiconductor layer and hence impact the mobility of charge carriers within the device active area while also advantageously decreasing the OFF current of the device.

Abstract: An organic field effect transistor includes a channel structure defining an active area located between a source and a drain. The channel structure includes a photoalignment layer and an organic semiconductor layer disposed directly over the photoalignment layer. The photoalignment layer is configured to influence an orientation of molecules within the organic semiconductor layer and hence impact the mobility of charge carriers both within the active area and adjacent to the active area.

Abstract: An optical device includes a first polarization selective reflector; a second polarization selective reflector positioned relative to the first polarization selective reflector so that the first polarization selective reflector directs first light having a first nonplanar polarization toward the second polarization selective reflector and the second polarization selective reflector directs at least a portion of the first light toward the first polarization selective reflector as second light. The optical device includes a first reflector positioned relative to the first polarization selective reflector so that the first polarization selective reflector directs at least a portion of the second light having a second nonplanar polarization toward the first reflector as third light.

Abstract: An optical film includes an organic solid crystal film formed of a contiguous organic solid crystal having a first dimension no less than 100 micrometer and a second dimension distinct from the first dimension no less than one centimeter. Methods for making the organic solid crystal film are also described.

Abstract: 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.

Abstract: An optical device includes a first polarization selective reflector; a second polarization selective reflector positioned relative to the first polarization selective reflector so that the first polarization selective reflector directs first light having a first nonplanar polarization toward the second polarization selective reflector and the second polarization selective reflector directs at least a portion of the first light toward the first polarization selective reflector as second light. The optical device includes a first reflector positioned relative to the first polarization selective reflector so that the first polarization selective reflector directs at least a portion of the second light having a second nonplanar polarization toward the first reflector as third light.

Abstract: In some embodiments, a device, such as a transducer, includes a polymer element disposed between electrodes, and a control circuit configured to apply electrical potentials having the same polarity to the electrodes. A separation distance between the electrodes may be increased by an electrostatic repulsion between the electrodes. Various other devices, systems, methods, and computer-readable media are also disclosed.

Abstract: A device, such as an electroactive device, may include primary electrode and a secondary electrode overlapping at least a portion of the primary electrode. An electroactive polymer element may include a composite polymer material and is disposed between and abuts each of the primary electrode and the secondary electrode. A phase change or other deformable medium such as a liquid, a gas, or a liquid-gas mixture may be disposed as inclusions within the polymer material. The device can be actuated by the application of a voltage between the electrodes and the attendant formation of a Maxwell stress, exposing the deformable medium to a source of radiation, changing a pressure of the deformable medium, or changing a temperature of the deformable medium, e.g., about a phase transformation temperature of the phase change medium.

Abstract: 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.

Abstract: An optical element is provided. The optical element includes a solid crystal including crystal molecules aligned in a predetermined alignment pattern at least partially defined by an alignment structure.

Abstract: A polymer thin film is characterized by a first in-plane refractive index (nx) along a first direction of the polymer thin film, a second in-plane refractive index (ny) along a second direction of the polymer thin film orthogonal to the first direction, and a third refractive index (nz) along a thickness direction substantially orthogonal to both the first direction and the second direction, where nx>nz>ny. Such a polymer thin film may exhibit one or more of (a) an in-plane birefringence of at least approximately 0.05, and (b) nx greater than approximately 1.7.

Abstract: A method is provided. The method includes providing an alignment structure at least partially defining a predetermined alignment pattern. The method also includes forming a solid crystal on the alignment structure. Crystal molecules of the solid crystal are aligned in the predetermined alignment pattern.

Abstract: In various embodiments, a method includes (1) applying a first voltage and a first current to an electroactive device that includes a nanovoided electroactive polymer, (2) measuring a second voltage and a second current associated with the electroactive device, (3) determining at least one of a position or a force output associated with the electroactive device, the position or the force based on the second voltage and the second current, and (4) applying a third voltage and a third current to the electroactive device based on the at least one of the position or the force output. Various other methods, systems, apparatuses, and materials are also disclosed.

Abstract: Embodiments of the disclosure are generally directed to systems and methods for switchable electroactive devices for head-mounted displays (HMDs). In particular, a method may include (1) applying an electric field to an electroactive element of an electroactive device via electrodes of the electroactive device that are electrically coupled to the electroactive element to compress the electroactive element, which comprises a polymer material defining nanovoids, such that an average size of the nanovoids is decreased and a density of the nanovoids is increased in the electroactive element, wherein the electroactive device is positioned at a distance from a user's eye, and (2) emitting image light from an emissive device positioned such that at least a portion of the image light is incident on a surface of the electroactive device facing the user's eye.

Abstract: A polymer layer includes a first in-plane refractive index extending along a first direction of the polymer layer, a second in-plane refractive index less than the first in-plane refractive index extending along a second direction of the polymer layer orthogonal to the first direction, a third refractive index along a direction orthogonal to both the first direction and the second direction, and a plurality of wrinkles extending along a surface of the polymer layer, where a difference between the first in-plane refractive index and the second in-plane refractive index is at least approximately 0.05, and the third refractive index is greater than the second in-plane refractive index.

Abstract: A waveguide display includes a substrate transparent to at least one of visible or near infrared light, and a grating on the substrate. The grating includes ridges formed using a birefringent material and is configured to selectively couple incident light in a first polarization state into or out of the substrate. The birefringent material in the ridges is characterized by an optic axis parallel to a plane that includes a grating vector of the grating.

Abstract: 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.

Abstract: A light-emitting disclosure (LED) and an LED array are disclosed. The LED includes a semiconductor junction for emitting light and an optical surface coupled to the semiconductor junction for outputting at least a portion of the light. The optical surface can include a grating structure configured to increase the portion of the light outputted by the optical surface, and/or a redirecting structure configured to redirect the portion of the light to form an output optical beam.

Abstract: An optical transformer includes a light source and an array of photovoltaic cells optically coupled to the light source, where at least a portion of the photovoltaic cells are connected in series. An optical connector such as a waveguide or an optical fiber may be disposed between an output of the light source and an input of the array of photovoltaic cells. Configured to generate a high voltage output, the optical transformer may be configured to power a device such as an actuator that provides a tunable displacement as a function of voltage.

Abstract: A display assembly includes a light source, a spatial light modulator (SLM) and a grating. The light source is configured to emit illumination light, the SLM is configured to receive the illumination light and reflect at least a portion of the illumination light. The grating is positioned to redirect the illumination light output from the light source toward the SLM, receive at least a portion of the reflected light from the SLM, redirect first light having a first polarization toward the light source, and transmit through the grating second light having a second polarization that is orthogonal to the first polarization. Also disclosed are operations performed by the display assembly.