111 results about "Thin-film interference" patented technology

An optical instrument including: a thermo-optically tunable, thin film, free-space interference filter having a tunable passband which functions as a wavelength selector, the filter including a sequence of alternating layers of amorphous silicon and a dielectric material deposited one on top of the other and forming a Fabry-Perot cavity structure having: a first multi-layer thin film interference structure forming a first mirror; a thin-film spacer layer deposited on top of the first multi-layer interference structure, the thin-film spacer layer made of amorphous silicon; and a second multi-layer thin film interference structure deposited on top of the thin-film spacer layer and forming a second mirror; a lens for coupling an optical beam into the filter; an optical detector for receiving the optical beam after the optical beam has interacted with the interference filter; and circuitry for heating the thermo-optically tunable interference filter to control a location of the passband.

Composite mirror systems include a wideband thin film interference stack having a plurality of microlayers and an optically thick layer having a refractive index greater than air but less than the smallest refractive index of the stack. The mirror systems can provide high reflectivity for light propagating in the stack and in the optically thick layer at supercritical angles, while avoiding degradation in reflectivity if dirt or other disturbances such as absorbing materials are present at the mirror backside for example due to contact with a support structure.

According to various embodiments and aspects of the present invention, there is provided a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

An optical method for measuring the temperature of a substrate material with a temperature dependent band edge. In this method both the position and the width of the knee of the band edge spectrum of the substrate are used to determine temperature. The width of the knee is used to correct for the spurious shifts in the position of the knee caused by: (i) thin film interference in a deposited layer on the substrate; (ii) anisotropic scattering at the back of the substrate; (iii) the spectral variation in the absorptance of deposited layers that absorb in the vicinity of the band edge of the substrate; and (iv) the spectral dependence in the optical response of the wavelength selective detection system used to obtain the band edge spectrum of the substrate. The adjusted position of the knee is used to calculate the substrate temperature from a predetermined calibration curve. This algorithm is suitable for real-time applications as the information needed to correct the knee position is obtained from the spectrum itself. Using a model for the temperature dependent shape of the absorption edge in GaAs and InP, the effect of substrate thickness and the optical geometry of the method used to determine the band edge spectrum, are incorporated into the calibration curve.

A security thread for embedding in or on a sheet such as a document, currency or packaging is disclosed, wherein the thread has a thin film interference structure deposited thereon. The structure may be a Fabry-Perot structure in the form of a single filter, or may be plural filters, spaced side-by-side. The thread appears to have separated interference filters deposited thereon. Preferably the thread is first roll coated with oil using an oil-ablation technique to remove deposited material in situ in the coating process. A magnetic layer may be deposited within, behind or in front of the thin film interference structure.

Methods and devices for the measurement of molecular binding interactions. Preferred embodiments provide real-time measurements of kinetic binding and disassociation of molecules including binding and disassociation of protein molecules with other protein molecules and with other molecules. In preferred embodiments ligands are immobilized within pores of a porous silicon interaction region produced in a silicon substrate, after which analytes suspended in a fluid are flowed over the porous silicon region. Binding reactions occur when analyte molecules diffuse closely enough to the ligands to become bound. Preferably the binding and subsequent disassociation reactions are observed utilizing a white light source and thin film interference techniques with spectrometers arranged to detect changes in indices of refraction in the region where the binding and disassociation reactions occur. In preferred embodiments both ligands and analytes are delivered by computer controlled robotic fluid flow control techniques to the porous silicon interaction regions through microfluidic flow channels.

A thin film interference filter system includes a plurality of stacked films having a determined reflectance; a modeled monitor curve; and a topmost layer configured to exhibit a wavelength corresponding to one of the determined reflectance or the modeled monitor curve. The topmost layer is placed on the plurality of stacked films and can be a low-index film such as silica or a high index film such as niobia.

Thin-film coatings, which for example have alternating layers of high and low refractive index materials, are shown to function as both positive and negative C-plates, in dependence upon the incident radiation. In particular, the shape of the retardance versus angle of incidence profile is found to be determined, at least in part, by the phase thickness of the thin film coating (i.e., the optical thickness in terms of the wavelength of the incident radiation, which may, for example, be expressed in degrees, radians, or as the number of quarter wavelengths). These thin film coatings are optionally integrated into anti-reflection coatings, thin film interference filters and/or other components to improve efficiency and/or functionality.

According to various embodiments and aspects of present invention, there is provided a dynamically tunable thin film interference coating including one or more layers with thermo-optically tunable refractive index. Tunable layers within thin film interference coatings enable a new family of thin film active devices for the filtering, control, modulation of light. Active thin film structures can be used directly or integrated into a variety of photonic subsystems to make tunable lasers, tunable add-drop filters for fiber optic telecommunications, tunable polarizers, tunable dispersion compensation filters, and many other devices.

The present disclosure relates to thin film optical interference filters. The filters include a substrate and a plurality of alternating material layers deposited on the substrate. When operated at about 45° angle of incidence, the filters exhibit at least one of improved polarization splitting, edge steepness, bandpass bandwidth, and blocking, relative to conventional thin film interference filters.

An inspection apparatus projects a laser beam on the surface of a SOI wafer and detects foreign matter on and defects in the surface of the SOI wafer by receiving scattered light reflected from the surface of the SOI wafer. The wavelength of the laser beam used by the inspection apparatus is determined so that a penetration depth of the laser beam in a Si thin film may be 10 nm or below to detect only foreign matter on and defects in the outermost surface and not to detect foreign matter and defects in a BOX layer. Only the foreign matter on and defects in the outermost surface layer can be detected without being influenced by thin-film interference by projecting the laser beam on the surface of the SOI wafer and receiving scattered light rays.

The invention belongs to the technical field of chemical materials, and particularly relates to a preparation method of a graphene oxide film or composite film capable of presenting different colors in different gas environments. The graphene oxide film can be applied in preparing gas sensors for detecting humidity and harmful gas. The preparation method specifically includes: preparing a grapheneoxide solution and a macromolecular solution, sequentially spin-coating the solutions on a modified silicon wafer substrate through a spin coater, and drying to obtain a color-changing graphene oxide/macromolecular composite film. Dispersity and selectivity of a graphene gas-sensitive material are improved; functionalized macromolecules are introduced, so that graphene lamellar structure is stabilized while gas-sensitive selection is improved, and a graphene/macromolecular schemochrome thin film which is flat and controllable in number of layer is prepared; a characteristic that conventionalgraphene gas-sensitive materials depend on electrochemical detection is broken through, an organic small molecule visual detection assembly array based on interference light response is built, and real-time, quick, accurate and visual detection of humidity and harmful gas is realized.

The present invention relates to a cutting insert comprising a body of sintered cemented carbide, cermet or ceramic or high speed steel or the superhard materials such as cubic boron nitride or diamond said body being provided with a hard and wear resistant coating including a thin outermost coloring non-oxide layer whereby said color is created by thin film interference.

A semitransparent OV device is formed using a partially transparent reflective layer having a thickness below the opaque point. For example, a partially transparent aluminum layer having a thickness of less than 20 nm, coated with a dielectric layer and an absorber layer, provides a color shifting optical stack that is partially transparent, so that an image or text printed on the substrate under the optical stack or on the opposite side of the substrate, is visible therethrough. In one embodiment, the substrate is light transmissive so that the OV foil is semitransparent so that information printed on paper and covered with such a foil may be read through this foil.

Disclosed is application of oblique angle of incidence, reflection and/or transmission mode spectroscopic ellipsometry PSI and/or DELTA, (including combinations thereof and/or mathematical equivalents), vs. wavelength data over an intermediate wavelength band range around a pass or reject band, to monitor and/or control fabrication of multiple layer high/low refractive index band-pass, band-reject and varied attenuation vs. wavelength thin film interference filters, either alone or in combination with transmissive non-ellipsometric electromagnetic beam turning point vs. layer data obtained at an essentially normal angle of incidence.

The present invention is directed to an assembly for use in detecting an analyte in a sample based on thin-film spectral interference. The assembly comprises a waveguide, a monolithic substrate optically coupled to the waveguide, and a thin-film layer directly bonded to the sensing side of the monolithic substrate. The refractive index of the monolithic substrate is higher than the refractive index of the transparent material of the thin-film layer. A spectral interference between the light reflected into the waveguide from a first reflecting surface and a second reflecting surface varies as analyte molecules in a sample bind to the analyte binding molecules coated on the thin-film layer.

A vertically extended cavity surface emitting laser (VECSEL) including intracavity frequency doubling. Conventional frequency-controlling elements, such as etalons, are replaced by thin-film interference filters or volume Bragg gratings.