Disclosed herein is an integrated photonics device including a frequency stabilization subsystem for monitoring and/or adjusting the wavelength of light emitted by one or more light sources. The device can include one or more selectors that can combine, select, and/or filter light along one or more light paths, which can include light emitted by a plurality of light sources. Example selectors may include, but are not limited to, an arrayed waveguide grating (AWG), a ring resonator, a plurality of distributed Bragg reflectors (DBRs), a plurality of filters, and the like. Output light paths from the selector(s) can be input into one or more detector(s). The detector(s) can receive the light along the light paths and can generate one or more signals as output signal(s) from the frequency stabilization subsystem. A controller can monitor the wavelength and can adjust or generate control signal(s) for the one or more light sources to lock the monitored wavelength to a target wavelength (or within a targeted range of wavelengths).

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body has the shape of two end-to-end Y's forming a central segment, two branch segments extending from each end of the central segment, and an extension segment extending from each of the four branch segments, to collectively form four unenclosed cell openings that are each semi-hexagonal in shape. Some embodiments include four reinforcement segments with each one extending into a respective cell opening, four voids with each one extending through respective adjacent branch and extension segments, an underbody gap formed under the central segment for refractory interlinking between cell openings, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed semi-hexagonal cell openings of adjacent anchoring devices cooperatively form substantially hexagonal cells.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body has the shape of two end-to-end Y's forming a central segment, two branch segments extending from each end of the central segment, and an extension segment extending from each of the four branch segments, to collectively form four unenclosed cell openings that are each semi-hexagonal in shape. Some embodiments include four reinforcement segments with each one extending into a respective cell opening, four voids with each one extending through respective adjacent branch and extension segments, an underbody gap formed under the central segment for refractory interlinking between cell openings, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed semi-hexagonal cell openings of adjacent anchoring devices cooperatively form substantially hexagonal cells.

A sensor comprises: a thin structure, which is configured to receive a force for deforming a shape of the thin structure and which is arranged above a substrate; and a waveguide for guiding an electro-magnetic wave comprising: a first waveguide part; and a second waveguide part; wherein the second waveguide part has a larger width than the first waveguide part; and wherein the first and the second waveguide parts are spaced apart by a gap which is sufficiently small such that the first and second waveguide parts unitely form a single waveguide, wherein one of the first and the second waveguide part is arranged at least partly on the thin structure and another of the first and the second waveguide part is arranged on the substrate.

Provided is a filter controlling expression derivation method including: preparing a Fabry-Perot interference filter of which distance between a fixed mirror and a movable mirror is controlled by balancing an electrostatic force and an elastic force; deriving a relational expression between a deflection amount and an elasticity index in which the elasticity index of the movable mirror is described as a quadratic or higher-order polynomial with the deflection amount of the movable mirror as a variable by performing predetermined measurement; and deriving a relational expression between a transmission wavelength of light transmitted through the Fabry-Perot interference filter and the voltage as a filter controlling expression based on the relational expression between the deflection amount and the elasticity index and a relational expression between the electrostatic force and the elastic force.

A method is provided for fabricating a passive optical sensor on a tip of an optical fiber. The method includes perpendicularly cleaving a tip of an optical fiber and mounting the tip of the optical fiber in a specimen holder of a photosensitive polymer three-dimensional micromachining machine. The method includes forming a three-dimensional microscopic optical structure within the photosensitive polymer that comprises a two cavity Fabry-Perot Interferometer (FPI) having a hinged optical layer that is pivotally coupled to a suspended structure. The method includes removing an uncured portion of the photosensitive polymer using a solvent. The method includes depositing a reflective layer on a mirror surface of the hinged optical layer. The method includes positioning the pivotally hinged optical layer to a closed position with the suspended structure, aligning the mirror surface with the cleaved tip of the optical fiber.

A method of making passive microscopic Fabry-Pérot Interferometer (FPI) sensor includes forming a three-dimensional microscopic optical structure on a cleaved tip of an optical fiber that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

An optical filter assembly comprising: a tuneable optical filter; a beam splitter assembly configured to split an input beam into an output beam, a reference beam, and a probe beam, and to direct the output beam and the probe beam through the tuneable optical filter, such that the probe beam is at an angle α to the output beam; a first detector configured to measure the intensity S0 of the reference beam; a second detector configured to measure the intensity S1 of the probe beam after it has passed through the filter; a controller configured to adjust the tuneable optical filter on the basis of the measured intensities of the reference and probe beams.

A method is provided for fabricating a passive optical sensor on a tip of an optical fiber. The method includes perpendicularly cleaving a tip of an optical fiber and mounting the tip of the optical fiber in a specimen holder of a photosensitive polymer three-dimensional micromachining machine. The method includes forming a three-dimensional microscopic optical structure within the photosensitive polymer that comprises a two cavity Fabry-Perot Interferometer (FPI) having a hinged optical layer that is pivotally coupled to a suspended structure. The method includes removing an uncured portion of the photosensitive polymer using a solvent. The method includes depositing a reflective layer on a mirror surface of the hinged optical layer. The method includes positioning the pivotally hinged optical layer to a closed position with the suspended structure, aligning the mirror surface with the cleaved tip of the optical fiber.

In a general aspect, a device is disclosed for providing a reference frequency of light. The device includes a housing having a first opening and a second opening. A first optical window covers the first opening and is coupled to the housing by a first ceramic bond that forms a hermetic seal around the first opening. A second optical window covers the second opening and is coupled to the housing by a second ceramic bond that forms a hermetic seal around the second opening. The device also includes an etalon disposed within an evacuated volume enclosed by at least the housing, the first optical window, and the second optical window. The device additionally includes one or more supports suspending the etalon in the evacuated volume. The one or more supports are formed of a material having a thermal conductivity no greater than 5 W/m.Math.K at room temperature.