In an illustrative configuration, a method for monitoring air quality is disclosed. The method includes accepting analyte gas into a cell and reflecting light rays into the analyte gas repeatedly across the cell into at least one sensor. The light scattered by particulate matter in the analyte gas and amount of spectra-absorption due to presence of a gaseous chemical is then measured. Based on the determined amount of spectra-absorption and the measured scattered light the gaseous chemical is then measured.

A system for imaging a scene, includes a plurality of optical sensors arranged on an integrated circuit and a plurality of sets of interference filters, where each set of interference filters of the plurality of sets of interference filters includes a plurality of interference filters that are arranged in a pattern and each interference filter of the plurality of filters is configured to pass light in a different wavelength range, where each set of interference filters of the plurality of interference filters is associated with a spatial area of the scene. The system includes a plurality of rejection filters arranged in a pattern under each set of interference filters, where each rejection filter of the plurality of rejection filters is configured to substantially reject light of predetermined wavelengths. The system further includes one or more processors adapted to provide a spectral response for a spatial area of the scene associated with the set of interference filters.

An optical device includes an optical member having a plurality of first optical layers and a plurality of second optical layers having a refractive index different from that of the first optical layer in which the first optical layers and the second optical layers are laminated, and a layer thickness changing electrode that changes a thickness of the first optical layer in a lamination direction of the first optical layers and the second optical layers, in which the optical member is provided in a pair, and the pair of optical members is disposed to face each other through a gap, and a gap changing driver that changes a dimension of the gap.

An optical microcavity device (10), an alignment structure for an optical device, and a method for aligning an optical device are disclosed. The optical microcavity device (10) comprises: a first optical reflector (20); a second optical reflector (30) opposed to the first optical reflector (20) along an optical axis (40), the first and second optical reflectors (20, 30) being spaced from each other forming an open space therebetween; wherein the first optical reflector (20) comprises a first cavity reflector (22) and a first alignment reflector (24), wherein the second optical reflector (30) comprises a second cavity reflector (32) and a second alignment reflector (34), the second cavity reflector (32) comprising a recess to provide an optical microcavity between the first and second cavity reflectors (20, 30), the optical microcavity having an optical cavity length of at most 50 μm and/or an optical mode volume of 100 μm3 or less; an EM radiation source (50) configured for illuminating the optical microcavity with EM radiation (52) to cause multi-pass interference within the optical microcavity; and an alignment system configured to: illuminate the first and second alignment reflectors (24, 34) of the first and second optical reflectors (20, 30) to generate an optical interference pattern (74); detect the optical interference pattern (74); and determine a relative orientation and/or separation of the first and second optical reflectors (20, 30) based on the detected optical interference pattern (74); the alignment system further comprising an actuator system (100, 102) configured to move the first and second optical reflectors (20, 30) relative to each other to change the relative orientation and/or separation of the first and second optical reflectors (20, 30) based on the determined relative orientation and/or separation. At least one of the first and second alignment reflectors (20, 30) may comprise an alignment structure comprising at least two reflective surface portions having different angular orientations.

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.

A spectral sensor comprising a Fabry-Perot interferometer having a pair of reflectors, a photodetector located beneath the Fabry-Perot interferometer, a capacitance measurement circuit configured to measure a capacitance of the Fabry-Perot interferometer, and a controller configured to control a voltage applied across the reflectors of the Fabry-Perot interferometer.

An optical filter device includes a wavelength variable interference filter that includes a pair of reflective films which face each other, and a fixed substrate in which one of the pair of reflective films is provided; a base to which the fixed substrate is fixed; and a fixing member which fixes one place on the fixed substrate to the base, a surface which is on other place of the one place of the substrate and the base are disposed with a gap therebetween.

In an illustrative configuration, a method for monitoring air quality is disclosed. The method includes accepting analyte gas into a cell and reflecting light rays into the analyte gas repeatedly across the cell into at least one sensor. The light scattered by particulate matter in the analyte gas and amount of spectra-absorption due to presence of a gaseous chemical is then measured. Based on the determined amount of spectra-absorption and the measured scattered light the gaseous chemical is then measured.

A pressure transducer and a fabrication method thereof are provided. The pressure transducer includes a light-emitting element, an interference light-filtering structure and a light-sensing element stacked on top of each other. The light-emitting element is configured to emit incident light onto the interference light-filtering structure. The interference light-filtering structure is configured to change its thickness in accordance with the pressure exerted on the pressure transducer and generate emergent light corresponding to the pressure. The light-sensing element is configured to detect the emergent light and generate an electrical signal corresponding to the emergent light.

A reflective spatial light modulator (SLM) made of an electro-optic material in a one-sided Fabry-Perot resonator can provide phase and/or amplitude modulation with fine spatial resolution at speeds over a Gigahertz. The light is confined laterally within the electro-optic material/resonator layer stack with microlenses, index perturbations, or by patterning the layer stack into a two-dimensional (2D) array of vertically oriented micropillars. Alternatively, a photonic crystal guided mode resonator can vertically and laterally confine the resonant mode. In phase-only modulation mode, each SLM pixel can produce a π phase shift under a bias voltage below 10 V, while maintaining nearly constant reflection amplitude. This high-speed SLM can be used in a wide range of new applications, from fully tunable metasurfaces to optical computing accelerators, high-speed interconnects, true 2D phased array beam steering, beam forming, or quantum computing with cold atom arrays.