A wavelength tunable interference filter includes a fixed substrate, a fixed reflection film that is provided on the fixed substrate, reflects part of incident light, and transmits at least part of the incident light, a movable reflection film that faces the fixed reflection film, reflects part of incident light, and transmits at least part of the incident light, and a fixed electrode that surrounds the fixed reflection film and has a light absorbing layer and a metal layer, and the light absorbing layer is disposed closer to the fixed substrate than the metal layer.

A passive microscopic Fabry-Prot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter 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.

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.

An optical filter includes: a first substrate; a second substrate opposed to the first substrate; a first reflecting film provided to the first substrate; a second reflecting film provided to the second substrate and opposed to the first reflecting film; a first electrode provided to the first substrate in a peripheral area of the first reflecting film; a second electrode provided to the first substrate in a peripheral area of the first electrode; a third electrode provided to the second substrate and opposed to the first electrode; and a fourth electrode provided to the second substrate and opposed to the second electrode.

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.

The invention relates to a method for producing a reference frequency f. According to the invention, the use of a first optical resonator (3a; 24) and of a second optical resonator (25) is provided, wherein the first resonator (3a; 24) has a first resonator mode having a first frequency f1 and the second resonator (25) has a second resonator mode having a second frequency f2, wherein the frequencies of the two resonator modes are functions of an operating parameter BP and assume the values f1 and f2 at a specified value BP.sub.0 of the operating parameter such that f1(BP.sub.0)=f1 and f2(BP.sub.0)=f2 apply, wherein the resonators (3a; 24, 25) are designed in such a way that the respective first derivatives of the frequencies f1(BP), f2(BP) with respect to BP or at least respective difference quotients around BP.sub.0 correspond within a deviation of at most 0.1%, wherein light of the first frequency f1 is stabilized to the first frequency f1 by means of the first resonator and light of the second frequency f2 is stabilized to the second frequency f2 by means of the second resonator, and wherein the difference between the stabilized frequencies f1 and f2, f=|f1f2|, is determined in order to obtain the stabilized reference frequency f.

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.

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.