2361 results about "Multi wavelength" patented technology

In embodiments of the present invention, systems and methods of a method and algorithm for creating a unique spectral fingerprint are based on the convolution of RGB color channel spectral plots generated from digital images that have captured single and/or multi-wavelength light-matter interaction.

A security mark having multiple optically orthogonal coaligned bar codes is produced using a reflection hologram visible substantially at only a first wavelength that is layered over a wavelength sensitive filter, which blocks light transmission at the first wavelength but transmits light at a second wavelength, and having beneath it an additional bar code visible through the hologram and the wavelength sensitive filter at the second wavelength. A validation means reads multiple holographic bar codes with light at the first wavelength by illuminating the hologram separately from multiple directions, and further reads the bar code beneath the wavelength sensitive filter by illuminating the mark with light of the second wavelength. By suitable choice of multi-directional and multi-wavelength illumination, multiple coaligned bar codes may be read in the same physical location with no mutual interference.

A currency processing device for receiving a stack of U.S. currency bills and rapidly processing all the bills in the stack, the device comprising: an input receptacle adapted to receive a stack of U.S. currency bills of a plurality of denominations, the currency bills having a wide dimension and a narrow dimension; a transport mechanism positioned to transport the bills, one at a time, in a transport direction from the input receptacle along a transport path at a rate of at least about 1000 bills per minute with the narrow dimension of the bills parallel to the transport direction; a currency bill sensor arrangement positioned along the transport path, the currency bill sensor comprising: i) a multi-wavelength light source configured to emit a first wavelength of light and a second wavelength of light; ii) a cylindrical lens positioned to receive the first and second wavelengths of light from the multi-wavelength light source, the cylindrical lens illuminating an elongated strip of light on a surface of one of the plurality of currency bills, the cylindrical lens being configured to receive light reflected from the surface of the one of the plurality of currency bills; iii) a photodetector positioned to receive the reflected light, the photodetector generating an electrical signal in response to the received reflected light; iv) a processor configured to receive the electrical signal generated by the photodetector; wherein, the processor is configured to determine whether the surface of the one of the plurality of currency bills is a primary surface or a secondary surface based on the electrical signal.

A loss-less, optical add/drop multiplexer according to the present invention includes a rare earth-doped fiber amplifier integrated with a wavelength-selective fiber path coupled between two directional optical transfer devices for selectively adding and dropping optical signals from a multi-wavelength signal, such as a wavelength division multiplexed optical signal. One or more fiber gratings are disposed along the length of the rare earth-doped fiber amplifier or between segments of the rare earth-doped fiber so that at least one grating is used for reflecting each optical signal that is expected to be added to or dropped from the multi-wavelength optical signal. By using this configuration, appropriate amplification is provided to compensate for losses in the add, drop, and through paths.

An optical spectroscopy apparatus determines the concentration of analyte in a specimen that utilizes a single radiation source which is hybrid laser comprising a semiconductor pump laser and small-cavity rare earth fiber laser where laser cavities of both lasers are butt coupled or otherwise optically coupled to form a plurality of laser cavities that produce a plurality of emission wavelengths, one which may be the pump laser emission wavelength at the output of the fiber laser thereby forming a multi-wavelength combined output where the wavelengths substantially match distinguishing spectral characteristic features along at least a portion of a characteristic optical spectrum of the analyte under examination. In lieu of complex data analysis of these wavelengths to determine values representing the concentration of the analyte in an examined specimen, the semiconductor pump laser or lasers are modulated as a plurality of tone frequencies, where at least a first of the modulation frequencies is below the maximum frequency response of the fiber laser so that the first modulation effectively modulates the pump emission wavelength and a first emission wavelength of the fiber laser in the hybrid laser combined output, and at least a second of modulation frequencies is above the maximum frequency response of the fiber laser so that the second modulation effectively modulates the pump emission wavelength but not the first emission wavelength of the fiber laser in the hybrid laser combined output. Further, one or more additional modulation frequencies may be applied to the pump laser which are intermediate of the first and second modulation frequencies where it is at least responsive to at least one further emission wavelength of the fiber laser and also provided in the hybrid laser combined output.

New optical coherence tomography (OCT) techniques are disclosed which are designed to improve OCT glucose concentration measure accuracy and are capable of being performed on a continuous basis. New multi-wavelength optical coherence tomography (OCT) techniques are also disclosed and designed to reduce artifacts do to water. New optical coherence tomography (OCT) techniques are also disclosed for determining local profusion rates, local analyte transport rates and tissue analyte transport rates as a measure of tissue health, disease progression and state and tissue transplantation effectiveness.

Methods and apparatus for measuring cerebral O₂ saturation and detecting cerebral hypoxia-ischemia using multi-wavelength near infrared spectroscopy (NIRS). Near-infrared light produced by an emitter is directed through brain tissue. The intensity of the light that passes through the brain tissue is measured using photodiode detectors positioned at distinct distances from the emitter. This process is conducted for at least three wavelengths of near-infrared light. One of the wavelengths used is substantially at an isobestic point for oxy-hemoglobin and deoxy-hemoglobin, but the other two may be any wavelengths within the near-infrared spectrum (700 nm to 900 nm), so long as one of the additional wavelengths is greater than the isobestic point and the other is less than the isobestic point. Tissue oxygenation is calculated using an algorithm derived from the Beer-Lambert law. Cerebral hypoxia-ischemia may be diagnosed using the calculated tissue oxygenation value.

Disclosed herein is a method for producing a multi-wavelength semiconductor laser device. The method comprises the steps of: forming first and second nitride epitaxial layers in parallel on a substrate for growth of a nitride single crystal; separating the first and second nitride epitaxial layers from the substrate; attaching the separated first and second nitride epitaxial layers to a first conductivity-type substrate; selectively removing the first and second nitride semiconductor epitaxial layers to expose a portion of the first conductivity-type substrate and to form first and second semiconductor laser structures, respectively; and forming a third semiconductor laser structure on the exposed portion of the first conductivity-type substrate.

To eliminate the drawbacks of false alarm problems due to mimic flame features of sunlight or moonlight reflecting on wave or mimic flame features of fabrics, animals or stage flames and alarm failures of methanol or ethanol burning flames or flames under a high illumination background condition, a multi-wavelength video image fire detecting system is disclosed consisting of a multi-wavelength video image fire detector, which is comprised of a color and near IR dual-mode camera, a color and B/W dual-mode camera, an image capture module, a processor and controller, an I/O module, a housing and a visible light and near IR view window, an alarm and indicate equipment, a setting and debugging system, a communication equipment, an area alarm and monitor system, and a pan & title and control system.

A multi-wavelength optical transmitting module includes a housing, an optical output block, an optical transmitting block, and an optical multiplexer (MUX) block. The housing has a first coupling hole and a second coupling hole respectively formed in opposite surfaces thereof. The optical output block is coupled to the first coupling hole of the housing, is connected to an optical signal connector, and includes a first lens. The optical transmitting block is coupled to the second coupling hole of the housing and is connected to an electrical signal connector. In addition, the optical transmitting block includes a plurality of transmitting devices which respectively output light having different wavelengths and are arranged parallel to the optical output block, and a plurality of second lenses which are arranged on a light output side of the transmitting devices to correspond respectively to the transmitting devices. The optical multiplexer (MUX) block is disposed within the housing, multiplexes optical signals of multiple wavelengths, which were output from the transmitting devices and passed through the second is lenses, and transmits the multiplexed optical signals to the optical output block.

A dust sensor includes a multi-wavelength light source, a receiver, and a controller. The light source emits light of different wavelengths. The receiver generates one or more acoustic wave measurement values based on acoustic waves irradiated from the light source to air particles. The controller controls at least one flickering cycle of the light source, determines the type particles based on the acoustic wave measurement values, and calculates the concentration of particles. The controller calculates the concentration of particles in proportion to an intensity of the acoustic wave measurement values, and determine the type of particles based on the acoustic wave measurement values. The acoustic waves are generated differently based on wavelengths of light emitted from the multi-wavelength light source.

The embodiment of the invention discloses a passive optical network system and a downlink transmission method thereof. The passive optical network system comprises an optical line terminal, an optical distribution network and a plurality of optical network units. The optical line terminal is used to send a downlink multi-wavelength optical signal composed of a plurality of downlink optical signal wavelength division multiplexing having different wavelengths, and the optical distribution network comprises a first-stage optical splitter, a plurality of second-stage optical splitters and a plurality of filter modules. The first-stage optical splitter is used to divide a downlink multi-wavelength signal sent by the optical line terminal into a plurality of downlink multi-wavelength signals, the plurality of filter modules are used to carry out filter processing on the plurality of downlink multi-wavelength signals to obtain a downlink single wavelength optical signal of which the wavelength corresponds to a channel central wavelength; wherein, the channel central wavelengths of the plurality of filter modules respectively correspond to the plurality of downlink optical signals having different wavelengths, the second-stage optical splitters are used to carry out spectral processing on the downlink single wavelength signal and then provide the downlink single wavelength signal to the optical network unit.

The present invention provides a slit-scan multi-wavelength confocal lens module, which utilizes at least two lenses having chromatic aberration for splitting a broadband light into continuously linear spectral lights having different focal length respectively. The present invention utilizes the confocal lens module employing slit-scan confocal principle and chromatic dispersion techniques and the confocal microscopy with optical sectioning ability and high resolution in spectral dispersion to establish a confocal microscopy method and system with long DOF and high resolution, capable of modulating a broadband light to produce the axial chromatic dispersion and focus on different depths toward an object's surface for obtaining the reflected light spectrum from the surface. Thereafter, the spectrum is spatially filtered by a slit and then a peak position with respect to the filtered spectrum along the scanning line is detected by a spectral image sensing unit for generating the sectional profile of the measured surface.

A structure of multi-wavelength light emitting device comprises multi-stacked active layer structure. Each stacked layer comprises lower energy bandgap well 4 and higher energy bandgap barrier layer 3 wherein at least one stacked layer in the device contains nanoparticles. As a result, the emitting wavelengths of the multi-stacked active layer structure consist parts (or all) of the emitting wavelengths come from the stack layers containing nanoparticles, and parts (or all) of the emitting wavelengths come from the stack layers not containing nanoparticles. In another embodiment, parts (or all) of the emitting wavelengths of the multi-stacked active layer structure can be also used to trigger one or more phosphorescences from the phosphors, thus the emitting wavelengths of such a phosphors converted light emitting device may come partially from the multi-stacked active layer itself and partially (or all) from the phosphors.

A method of producing an active optical waveguide having asymmetric polarization, said method comprising the steps of (a) providing an active optical waveguide (10) comprising: (i) a transverse refractive index profile (21) comprising a guiding region (11), an intermediate region (13), and a non-guiding region (12); (ii) a transverse photorefractive dopant profile (31) comprising a constant or graded photorefractive dopant concentration within at least one of the guiding, non-guiding and intermediate regions, except that the photorefractive dopant is not located solely in the guiding region; and (iii) exhibiting in said guiding region, intermediate region, or both, light guiding modes having different polarizations; and (b) exposing at least a part (10a, 10b) of the active optical waveguide to an effective transverse illumination of light (20) reacting with the photorefractive dopant and modifying said transverse refractive index profile; said part of the active optical waveguide being exposed to a fluence selectively suppressing the propagation of the light guiding modes having different polarizations so that the propagation of one mode is less suppressed than the propagation of the other mode(s). Such an active optical waveguide, single polarization mode optical waveguide lasers and multi-wavelength single polarization mode optical waveguide lasers comprising such an active optical waveguide, methods of their production, and their uses in telecommunications, in spectroscopy, in sensors and in absolute calibrated laser light sources.

A system and a method for quantum key distribution over a multi-user wavelength division multiplexing (WDM) network are disclosed. The system comprises a tunable or multi-wavelength transmitter; a plurality of receivers, each assigned a receiving-wavelength; and a multi-user WDM network linking the transmitter to the receivers. The transmitter can select a receiver among the receivers to be communicated therewith and transmit quantum signals to the selected receiver over the WDM network. The quantum signals are at a wavelength equal to a receiving-wavelength of the receiver. Therefore the WDM network allows quantum signals to be communicated between the transmitter and the receivers by wavelength routing.

Stereoscopic device including at least two apertures, each including a light valve, a multi wavelength light sensor array and a controllable multi wavelength illumination unit, producing at least two alternating beams of light, each of the beams of light is characterized as being in a different range of wavelengths, wherein each light valve is operative to open at a different predetermined timing and wherein the multi wavelength light sensor array detects a plurality of images, each of the images corresponding to a predetermined combination of an open state of a selected one of the light valves and a selected one of the modes.