The present invention generally relates to optoelectronic compounds, including certain nitrobenzoyl compounds, for example 2-(4-nitrobenzoyl)oxazole. In certain embodiments, these compounds can be used as electrochromic media in devices requiring change of optical absorbance or transmittance as a function of applied voltage. Examples of such devices include electrochromic mirrors, windows, displays, or the like. One specific example is solar and thermal control by smart, dynamic windows for energy-efficient buildings. Other embodiments of the invention are generally directed to systems and devices using such compounds, methods of using such compounds, e.g., to control the absorbance or transmittance of light, kits involving such compounds, or the like.

The disclosed electronic shutter may include (1) an optical structure including a medium through which light from an environment passes to a lens of a camera for capturing an image of the environment; and (2) a controlling circuit that (a) detects a first condition of a signal, where the first condition indicates an activation of the camera, (b) controls, in response, to the first condition, the optical structure such that the medium attains a transparent optical state, (c) detects a second condition of the signal, where the second condition indicates a deactivation of the camera, and (d) controls, in response to the second condition, the optical structure such that the medium attains a non-transparent optical state in a manner that prevents visual detection of the lens from the environment. Various other methods and systems are also disclosed.

An electro-optic display having a viewing surface through which a user views the display, a bistable, electrophoretic medium, and at least one electrode arranged to apply an electric field to the electrophoretic medium, the display further comprising at least 10 micromoles per square meter of the viewing surface of at least one compound having an oxidation potential more negative that about 150 mV with respect to a standard hydrogen electrode, as measured at pH 8, where the compound is a sulfite salt or a salt of titanium (III), vanadium (II), iron (II), cobalt (II) or copper (I), a hydroquinone, a catechol, a dihydropyridine or a metallocene.

A transmittance-variable layer and a transmittance-variable device including the same are disclosed herein. In some embodiments, a transmittance-variable device includes a polarization layer and a transmittance-variable layer disposed on the polarization layer, wherein the transmittance-variable layer includes a first base layer disposed on the polarization layer and a spacer fixed on a surface of the first base layer opposite to the polarization layer, and a second base layer facing the first base layer and spaced apart from the first base layer by the first spacer, wherein the first spacer maintains a gap between the first and second base layers, and a first light modulating material disposed in the gap.

An apparatus comprising a switchable optical filter comprising a layer of switchable material, the switchable material comprising a photochromic/thermochromic, a photochromic/photochromic, or a photochromic/electrochromic compound; a first light source providing light of a wavelength that causes the switchable material to transition from a faded state to a dark state, or a dark state to a faded state; and a switch for controlling activation of the first light source.

An apparatus comprising a switchable optical filter comprising a layer of switchable material, the switchable material comprising a photochromic/thermochromic, a photochromic/photochromic, or a photochromic/electrochromic compound; a first light source providing light of a wavelength that causes the switchable material to transition from a faded state to a dark state, or a dark state to a faded state; and a switch for controlling activation of the first light source.

An optoelectronic device, including a tunable optical filter or tunable optical filter with photodiode, uses voltage differentials to filter an optical signal passing along an optical path. A membrane has an electrode and is disposed adjacent a fixed mirror and another. A central portion of the membrane is distanced from the fixed mirror and has an aperture in which a second mirror is disposed. This second mirror translates with the membrane at a freespace gap relative to the fixed mirror when the electrodes are subject to the voltage differentials. In turn, the freespace gap is configured as a Fabry-Perot etalon to pass one or more spectral frequencies of the optical signal along the optical path. The membrane is shaped and reinforced to limit possible bowing. The translatable mirror in the aperture of the membrane is also shaped and reinforced to limit it from possible bowing as well.

An optoelectronic device, including a tunable optical filter or tunable optical filter with photodiode, uses voltage differentials to filter an optical signal passing along an optical path. A membrane has an electrode and is disposed adjacent a fixed mirror and another. A central portion of the membrane is distanced from the fixed mirror and has an aperture in which a second mirror is disposed. This second mirror translates with the membrane at a freespace gap relative to the fixed mirror when the electrodes are subject to the voltage differentials. In turn, the freespace gap is configured as a Fabry-Perot etalon to pass one or more spectral frequencies of the optical signal along the optical path. The membrane is shaped and reinforced to limit possible bowing. The translatable mirror in the aperture of the membrane is also shaped and reinforced to limit it from possible bowing as well.

Disclosed are systems, methods, and structures for broadband phase shifting for quantitative phase microscopy (QPI) that advantageously allows for a greater useable wavelength range for QPI wherein either/both illumination paths and/or scatter paths: 1) propagate through a reflective objective; 2) become quantifiably phase-shifted utilizing broadband mirror surfaces; 3) attenuate the relatively bright illumination paths to maximize contrast; and 4) recombine at a sensor plane for quantitative analysis.

A display apparatus of the present disclosure includes: a first optical system that generates illumination light whose light emitting luminance is variable; a light modulation unit that transmits the illumination light from the first optical system and whose transmissivity is variable; a second optical system that includes a light modulation device and optically modulates the illumination light from the first optical system by using a pulse width modulation technology, the illumination light having passed through the light modulation unit; and a control unit that controls the light emitting luminance of the illumination light from the first optical system and the transmissivity of the light modulation unit in any combination.