1050 results about "Interference filter" patented technology

The invention relates to a transdermal analyte monitoring system comprising a medium adapted to interface with a biological membrane and to receive an analyte from the biological membrane and an electrode assembly comprising a plurality of electrodes, wherein the medium is adapted to react continuously with the analyte, an electrical signal is detected by the electrode assembly, and the electrical signal correlates to an analyte value. The analyte value may be the flux of the analyte through the biological membrane or the concentration of the analyte in a body fluid of a subject. The medium may comprise a vinyl acetate based hydrogel, an agarose based hydrogel, or a polyethylene glycol diacrylate (PEG-DA) based hydrogel, for example. The surface region of the electrode may comprise pure platinum. The system may include an interference filter located between the biological membrane and the electrode assembly for reducing interference in the system. The system may comprise a processor programmed to implement an error correction method that corrects for sensor drift.

Within a method of making an optical interference filter, sample spectra and measurements of a predetermined characteristic associated with respective spectra are provided. Upon selection of an initial number of filter layers and a thickness for each layer, a transmission spectrum is determined. Each sample spectrum is applied to a regression formula that relates interaction of light with the transmission spectrum to a regression value. A comparison relationship between the calculated regression values and the sample measurements is defined and optimized, wherein thickness of each layer is an optimization variable.

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.

A novel class of optoelectronic devices incorporate an interference filter. The filter includes at least two optical cavities. Each of the cavities localizes al least one optical mode. The optical modes localized at two cavities are at resonance only at one or at a few discrete selective wavelengths. At resonance, the optical eigenmodes contain one mode having a zero intensity at a node position between the two cavities, where this position shifts as a function of the wavelength. A non-transparent element, which is preferably an absorbing element, a scatterer, or a reflector, is placed between two cavities. At a discrete selective wavelength, when the node of the optical mode matches with the non-transparent element, the filter is transparent for light. At other wavelengths, the filter is not transparent for light. This allows for the construction of various optoelectronic devices showing a strongly wavelength-selective operation.

The invention relates to a transdermal analyte monitoring system comprising a medium adapted to interface with a biological membrane and to receive an analyte from the biological membrane and an electrode assembly comprising a plurality of electrodes, wherein the medium is adapted to react continuously with the analyte, an electrical signal is detected by the electrode assembly, and the electrical signal correlates to an analyte value. The analyte value may be the flux of the analyte through the biological membrane or the concentration of the analyte in a body fluid of a subject. The medium may comprise a vinyl acetate based hydrogel, an agarose based hydrogel, or a polyethylene glycol diacrylate (PEG-DA) based hydrogel, for example. The surface region of the electrode may comprise pure platinum. The system may include an interference filter located between the biological membrane and the electrode assembly for reducing interference in the system. The system may comprise a processor programmed to implement an error correction method that corrects for sensor drift.

A wavelength discretely tunable semiconductor laser that addresses wide wavelength tuning range, is mode hopping free, has high output power, has fast wavelength switching time, is wavelength locking free and is relatively simple. Four exemplary embodiments disclosed herein utilize a wavelength discretely tunable semiconductor laser that comprises a discretely tunable filter and laser amplifier. In the first embodiment, the tuning element comprises a pair of cascade Fabry-Perot filters, each having a plurality of characteristic narrow transmission passbands that pass only the cavity mode under the passband. The spacing between the narrow transmission passbands are slightly different in one filter from the other filter so that only one passband from each filter can be overlapped in any given condition over the entire active element gain spectral range, thereby permitting lasing only at a single cavity mode passed by the cascade double filters. One of the two etalon filters can be made with a plurality of transmission passbands predetermined by industry, application and international standards, making this element an intra-cavity wavelength reference and eliminating further wavelength locking needs for the tunable laser. In a second embodiment, one of the two etalons is replaced by a wedge filter. The filter optical path change and thus the transmission passband shift are achieved by translating the wedge filter in a direction perpendicular to the optical axis. In a third embodiment, one of the two etalon filters is replaced by a polarization interference filter. The polarization interference filter consists of an electro-optically-tunable birefringent waveplate, a fixed birefringent waveplate, the laser cavity and T.E. polarization light emitted from the laser diode. In a fourth embodiment, the laser and wavelength tuning structure are integrated on a semiconductor substrate by epitaxy processes.

A communication system is disclosed that allows high data-rate transmission of data between components. N-bit parallel data is transmitted in K-frequency separated channels on the transmission medium so as to fully take advantage of the overall bandwidth of the transmission medium. Additionally, a cross-channel interference filter in a receiver section corrects for cross-channel interference in the communication system. As a result, a very high data-rate transmission can be accomplished with low data-bit transmission on individual channels. A transmitter system and a receiver system are described for the communication system.

A stereoscopic display system employs narrowband illumination light beams and passive glasses with built-in interference filters. The system is also compatible with multiple viewing functions.

A portable infusion monitoring system displays the liquid level and flow rate data during infusion process, as well as gives an alarm for patents and nurses in hospital as the medical liquid in an IV bottle drops to a predetermined low level. This system comprises a set of liquid level sensor, a microprocessor, and a monitor terminal. The liquid level sensor generates an electric signal related to the liquid level inside the IV bottle. The microprocessor analyzes the electric parameters detected from the electric signal, and obtains the liquid level data. The liquid level data are sent to the monitor terminal for display, and an alarm is activated when the medical liquid inside the IV bottle drops to a predetermined low lever. Further functions of the monitor terminal includes an automatic switch to cut off the IV feeding process and send the alarm signal to a nurse station through signal network by wire or wirelessly. Several interference filtering methods are applied to increase signal/noise ratio, and therefore warrant the operation reliability.

An imaging system of the invention includes an image array sensor including a plurality of pixels. Each of the pixels generate a signal indicative of the amount of light received on the pixel. The imaging system further includes an analog to digital converter for quantizing the signals from the pixels into a digital value. The system further includes a memory including a plurality of allocated storage locations for storing the digital values from the analog to digital converter. The number of allocated storage locations in the memory is less than the number of pixels in the image array sensor. According to another embodiment, an imaging device includes an image sensor having a plurality pixels arranged in an array; and a multi-layer interference filter disposed over said pixel array, said multi-layer interference filter being patterned so as to provide filters of different colors to neighboring pixels or groups of pixels.

The present invention provides methods and compositions for authentication of articles and counterfeit deterrence using non-holographic micro-optics and microstructures having a surface relief greater than a few microns. Embodiments of the present invention disclose a range of distinctive optical effects obtained from micro-optic systems incorporating micro lenses, non-imaging collectors, prisms, wave guides, mirrors, gratings, structural interference filters, and photonic crystal microstructures.

Optical lenses are described and include a polymeric interference filter disposed on a curved polymeric substrate. The optical lens has an average light transmission of less than 2% across a band of blue light from 400 nm to at least 420 and up to 440 nm and substantially transmits blue light greater than 450 nm.

This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.

Photoelectric converters are arranged two-dimensionally in a semiconductor substrate. A planarizing layer, a light shielding film, a further planarizing layer and condenser lenses are formed sequentially on the semiconductor substrate and the photoelectric converters. The light shielding film has apertures at positions corresponding to the photoelectric conversion devices. Multilayer interference filters that transmit either a red, green or blue wavelength component of light are disposed in the apertures.

The present invention relates to a heat filter and a process for manufacturing this filter.

This heat filter may for example be used to filter surgical or examination lighting composed of a light source which emits energy, or radiation, in the visible and infrared ranges. It allows the light emitted by this source to be filtered so as to prevent infrared radiation from hindering the surgical team or the patient.

It includes a substrate, at least one layer of an infrared reflecting material, and a coating forming an interference filter in the visible range.

The invention process includes the deposition on a substrate of a layer of an infrared reflecting material and the deposition on this layer of an interference filter in the visible range.

Devices and methods of accurately determining optical wavelengths, such as the Bragg wavelengths of an FBG sensor array. Wavelength-swept light having a characteristic spectrum is swept over a bandwidth and is applied to an interference filter. The interference filter produces an optical spectrum having one or more reference peaks that are identifiable because of the characteristic spectrum. The optical spectrum is converted into electrical signals having at least one electrical signal that is identifiable because of the characteristic spectrum. The identifiable electrical signal is used by a signal processor as an absolute, high accuracy wavelength reference. Temperature compensation or temperature stabilization can compensate the characteristic wavelength. Fiber Bragg sensor systems can use the wavelength reference to determine the Bragg wavelength of FBG elements. The characteristic spectrum can be imparted by the light source or an optical element such as a transmission line filter.

A component analyzer includes a casing, a light source unit, a light incident unit guiding light from a test object into the casing, a tunable interference filter extracting light having a predetermined wavelength from the incident light, an imaging unit receiving the extracted light and taking a spectroscopic image, a control unit performing a component analysis of the test object based on the spectroscopic images, and a display displaying a component analysis result. The light incident unit, the imaging unit, and the control unit are provided within the casing. The tunable interference filter includes a fixed substrate having a fixed reflection film and a movable substrate provided to face the fixed substrate and having a movable reflection film opposed to the fixed reflection film across a gap between reflection films, and an electrostatic actuator changing the gap between reflection films.

The present invention relates to an optical device for splitting incident unpolarized white light into simultaneously spectrally separated and orthogonally polarized light beams having complementary primary color bands by using interference filters for primary color bands such as the Infitec filters. The optical device embodying the present invention can be used in, for example, illumination systems for passive stereoscopic 3D display systems. When used in the stereoscopic 3D display system, the present invention provides a high degree of spectral and polarization separation of the individual stereoscopic images and the increased efficiency in use of illumination light compared to the conventional stereoscopic projection systems.

An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO₂, SiO_x, SiO_xN_y, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Added nitrogen in the a-Si:H,N layers provides improved transmission in the passband without a large decrease in refractive index observed in a-Si:H with comparable transmission. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO₂ as the low index layers.

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.

In a measuring probe (40) according to the present invention, measuring light is split into a two or more through a split optical system (12), and, when each split light is received by a light-receiving sensor (13B, 13B, 15B) through an interference filter (13A, 14A, 15A) serving as a color filter, the split light is introduced into the interference filter (13A, 14A, 15A) through a collecting lens group (123C, 14C, 15C) formed as a substantially bilateral telecentric system. The interference filter (13A, 14A, 15A) is formed to obtain a transmittance characteristic corresponding to a measurement parameter, depending on a condition of an intensity distribution with respect to incidents angles of light incident on the interference filter (13A, 14A, 15A). Thus, the measuring probe (40) according to the present invention can reduce an influence of a deviation in the transmittance characteristic due to incident angles, even using the interference filter (13A, 14A, 15A).

The invention discloses a method and a system for resisting dense forwarding type defraud interference of an airborne radar, and the resistance of dense forwarding type defraud interference is realized through an interference scout module and an interference filter and elimination module. Interference scout is used for carrying out the PD (probability of defraud) treatment on data received by a radar; the CFAR (constant false alarm rate) detection is carried out on data in a clear area; a detection result direction of arrival is estimated; an interference direction of arrival is estimated with combination of the detection result of a plurality of wave positions. In the interference filter and elimination treatment, a sum beam pointing to the interference direction is formed according to an interference scout result; the sum beam pointing to the interference direction is used as an auxiliary passageway, an existing space passageway is used as a main passageway, the method of GSC (gain scheduling control) is adopted to filter and eliminate interference, and the channel covariance matrix of the interference is estimated according to an interference sample selected from the clear area. By adopting the method and the system, the difficult problem of inhibition on dense forwarding type defraud interference is solved, the dense forwarding type interference is fundamentally filtered and eliminated, false alarms caused by the dense forwarding type interference are reduced, adverse effects on a CRAR detection threshold and the STAP (space time adaptive processing) performance are eliminated, the detection performance of a radar target is improved, the system is simple and easy to realize, and an engineering application value is provided.

The invention discloses a rapid lens flaw detection method and an apparatus thereof. The method comprises the following steps: equally dividing the surface of a lens to be detected into n<2> parts, respectively obtaining the images of all the parts, and obtaining n<2> images within a preset time which is used for controlling the image obtaining rate; 2, carrying out median filtering, black hat transformation and binary processing on the n<2> images respectively, and partitioning off defective images; 3, carrying out opening operation on the defective images to filter out non-flaw interference parts; and 4, drawing contours of the defective images subjected to non-defective interference filter, there are flaws on the surface of the lens to be detected if there is a counter, and no flaws are on the surface of the lens to be detected if there is no counter. The rapid lens flaw detection method provided in the invention allows scratches on the lens to be clearly detected through a surface defect detection method based on the mathematical morphology under the high speed motion of a platform, and defect types to be effectively discriminated, and has the characteristics of fast speed, objective detection result and the like.