1024 results about "Multi wavelength" patented technology

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.

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.

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 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.

The invention discloses a multi-wavelength high-sensitivity online monitor of multi-component NH3 and H2O based on semiconductor laser absorption spectroscopy. It contains host chassis and open long-path system. Equip power receptacle, switch, fiber connector and data transmission interface. It is characterized in that: there are near-infrared semiconductor laser, semiconductor laser controller, phase-locked amplifier, signal generator, data collecting and controlling module and infrared detector in host chassis which is connected with field optical system by fiber. Open optical system contains send-receive optical telescope and multielement reflector array. Optical telescope has input and output fiber couplers. The device realizes simultaneous testing of gas multi-component by using multi-wavelength and frequency division multi-signal detecting technique.

A laser warning receiver is disclosed which has up to hundreds of individual optical channels each optically oriented to receive laser light from a different angle of arrival. Each optical channel has an optical wedge to define the angle of arrival, and a lens to focus the laser light onto a multi-wavelength photodetector for that channel. Each multi-wavelength photodetector has a number of semiconductor layers which are located in a multi-dielectric stack that concentrates the laser light into one of the semiconductor layers according to wavelength. An electrical signal from the multi-wavelength photodetector can be processed to determine both the angle of arrival and the wavelength of the laser light.

This is a double wavelength semiconductor laser unit having a first laser emitting a light of a first wavelength and a second laser emitting a light of a second wavelength different from the first wavelength. The first and second lasers are merged on a substrate. The first laser has a bulk active layer whose film thickness is 0.01 mum or more and 0.1 mum or less. And the second laser has an MQW active layer constituted by stacked structure composed of a quantum well layer and a barrier layer. By employing the bulk active layer for the first laser, it is possible to reduce the band gap discontinuity induced at a boundary between a cladding layer and the bulk active layer, and then decreases an operational voltage, and further improve the reliability of the first laser.

Multi-wavelength light having a frequency band equal to or greater than the FSR of an AWG is demultiplexed into individual wavelength channels, and power level deviations between wavelength channels are suppressed. An optical demultiplexer includes a wavelength-group demultiplexer that demultiplexes multi-wavelength light into wavelength groups formed from wavelength channels, and channel demultiplexers that demultiplex each wavelength group into wavelength channels light. An optical multiplexer includes channel multiplexers that multiplex modulated signal light of each wavelength channel for each wavelength group, and a wavelength-group multiplexer that multiplexes, for each wavelength group, WDM signal light output from the channel multiplexers. The FSR of the wavelength-group multiplexer/demultiplexer is set to be equal to or greater than the frequency band of the multi-wavelength light. The channel multiplexer/demultiplexer is an AWG in which the FSR is approximately the full width at half maximum of the transmission characteristics of each port of the wavelength-group multiplexer/demultiplexer.

Multi-wavelength dental light curing guns or devices are disclosed. The multi-wavelength dental light curing guns or devices include a user handle attached to a light source support. A first light source is mounted on the light source support and is operable to project a first light beam of a first wavelength along a first light path, the first wavelength being capable of initiating polymerization of a first photopolymerizable dental composition. A second light source is mounted on the light source support and is operable to emit a second light beam of a second wavelength along a second light path, the second wavelength being capable of initiating polymerization of a second photopolymerizable dental composition different than the first dental composition, wherein the first light path does not intersect the second light path.

An authentication system may comprise: a first light source, a second light source, and at least three optically filtered light sensing devices for detecting analog emission intensity in a spectral sensitivity range, wherein each light sensing device is in operable communication with the first light source and/or the second light source. The first light source can have a first light source spectral distribution and can be capable of providing sufficient excitation to produce a photoluminescent emission from a medium comprising a luminescent tag and a color. The second light source can have a visible multi-wavelength spectral distribution and can be capable of providing sufficient visible multi-wavelength illumination of the medium to generate a second analog response, wherein the second analog response is different from the photoluminescent emission. Each light sensing device can have a different device spectral sensitivity range which includes at least a portion of the visible multi-wavelength spectral distribution, with the device spectral sensitivity range of at least one of the light sensing devices including at least a portion of a desired photoluminescent emission wavelength range.

The present invention is a multi-wavelength diagnostic imager. In one embodiment, the present invention includes an apparatus and method for noninvasive evaluation of a target versus a non-target, comprising: one or more light sources having at least one emission spectra directed at the target wherein the position, orientation and intensity of light sources is varied to control near-surface reflectance and are directed at less than the entire target; and one or more detectors positioned to capture light reflected from the target into two or more spatial images of the target at two or more times, wherein the spatial images are used to distinguish between the target and the non-target.

The invention discloses a passive optical network system, an optical line terminal, optical network units, a method for generating bandwidth mapping information and a method for processing the bandwidth mapping information. When implemented, the system can allow a plurality of ONUs using different uplink wavelengths to synchronously transmit uplink data during the same time period, thereby making full use of the uplink bandwidth of a GPON system, meeting demands of a user for uplink bandwidth and avoiding serious uplink bandwidth waste caused when a dynamic bandwidth distributing mechanism of the prior GPON system is applied to a multi-wavelength uplink GPON system.

An intravenous implantable optical sensor assesses the relative absorbance of multiple wavelengths of light in order to determine oxygen saturation. The calculation of oxygen saturation is enhanced by use of a function of hematocrit which is derived from the relative absorbance of light of an isobestic wavelength along two different length paths through the blood. The use of the hematocrit-dependent term and multiple wavelengths of light to calculate oxygen saturation provides results that are less susceptible to noise and variation in hematocrit and thus provides a more accurate measure of oxygen saturation over a wider range of conditions than previously possible. The optical sensor may form part of an implantable system which performs the calculation of oxygen saturation and uses the results for a diagnostic or therapeutic purpose.

This invention discloses a kind of optical-mechanical system which is used in photoetching machine and on it, and its matching system includes light source module supplying light. Transmitting light beam, vertical illumination crystal plate cyclicity optical structure alignment mark lighting unit. To collect alignment mark the multilevel diffracted ray by using microobjective. To realize the multi-wavelength separated by using the polychromatic light separated system. To correspond the positive and negative diffraction spectrum of the alignment mark with the imaging units by using level-bonded grating system. To measure the changing of the light intensive and the phase for the several wave-length and the levels spectrum spot by using the differential Mohr-message detection method, so we can got the detective unit of the alignment mark message. The level-bonded grating system includes the grating, the reflecting mirror and the prism, to overlay the +1-+n level and the -1--n level of the alignment mark message mark with the positive and negative diffraction spot. It can supply highly alignment accuracy and stability.

An optical network terminator for terminating and reducing the accumulated noise in optical networks, particularly ring based networks. The terminator eliminates problems of noise accumulation from amplifier spontaneous emission (ASE), thermal noise, etc., while providing bi-directional communications in the optical network. The optical network may have any topology including ring, star, mesh, point-to-point, etc. In the case of an optical ring, the ring is broken and an optical terminator is placed in line therewith. The optical network terminator includes a filer such as an optical demultiplexer/multiplexer or Fiber Bragg Grating (FBG) based filter. Each individual wavelength of light is filtered and a multi-wavelength optical output is generated whereby the noise accumulation is removed. Each channel is adapted to only pass a band-limited signal around the center frequency corresponding to the wavelengths supported by the particular optical ring network. Channel equalization uses variable optical attenuators and monitors in line with each channel. Channels currently not in use may be disconnected from the ring remotely by setting the corresponding optical attenuator to a low enough level.

Multiple-wavelength VCSEL array apparatus and method having a high contrast grating (HCG) mirror which can be implemented on a single substrate in which only the dimensions of the HCG (e.g., duty cycle or the period) need be changed to alter the wavelength of a given VCSEL in response to changing the reflectivity phase of the HCG mirror. The HCG can be defined by any desired lithographic process. By using a broadband HCG mirror a large wavelength span over 100 nm is provided, such as covering the entire C-band. The HCG multi-wavelength VCSEL array enables single-transverse mode emission and polarization control and scalability with respect to wavelength.

Laser for thermal shrinkage of soft tissue of uvula, soft palate, nasal turbinate or tongue base for the treatment of snoring, nasal obstruction or sleep apnea are disclosed. The preferred laser includes infrared laser about 0.7 to 1.85 micron, pulse duration about 100 microsecond to 5 seconds, spot size of about 2 to 5 mm and power of about 2 to 20 W at the treated area. The laser energy is delivered to the treated area by an optical fiber and a hand piece to cause a localized temperature about 65 to 85 degree Celsius for sufficient shrinkage of the treated soft tissues. Optical fiber bundles to produce high-power diode laser output or multi-wavelength are also disclosed.

In certain embodiments, the invention relates to optical probes and methods for conducting Raman spectroscopy of a material at multiple excitation wavelengths. The probes and methods utilize optical elements to focus outputs from a plurality of light sources or lasers onto a sample, collect backscattered light from the sample, separate Raman spectra from the backscattered light, and provide at least one output containing the spectra. By utilizing multiple excitation wavelengths, the probes and methods avoid Raman measurement issues that may occur due to, for example, fluorescence and/or luminescence.

Optical signals are received from a free-space link by directing received light onto a plurality of microlenses and then directing light received through each of the microlenses into a respective single mode optical fiber (SMF). Light beams from the SMFs are combined into a single light beam in one SMF. The single light beam is amplified with a multi-wavelength fiber amplifier and attenuated with a variable optical attenuator. The power gain of the multi-wavelength fiber amplifier and the attenuation of the variable optical attenuator are controlled. The single light beam is directed into a fiber optic communication system that is optically coupled to the variable optical attenuator.

An imaging apparatus is disclosed. The imaging apparatus includes a source of electromagnetic radiation that is configured to emit electromagnetic radiation at two or more wavelengths through an imaging volume. The imaging apparatus also includes an ultrasound transducer that is configured to direct ultrasound waves through the imaging volume such that electromagnetic radiation passing through the imaging volume is modulated at the frequency of the ultrasound waves. The imaging apparatus further includes one or more electromagnetic radiation detectors that are configured to detect the modulated electromagnetic radiation from the imaging volume.

An arrangement for achieving and maintaining high efficiency coupling of light between a multi-wavelength optical signal and a relatively thin (e.g., sub-micron) silicon optical waveguide uses a prism coupler in association with an evanescent coupling layer. A grating structure having a period less than the wavelengths of transmission is formed in the coupling region (either formed in the silicon waveguide, evanescent coupling layer, prism coupler, or any combination thereof) so as to increase the effective refractive index “seen” by the multi-wavelength optical signal in the area where the beam exiting/entering the prism coupler intercepts the waveguide surface (referred to as the “prism coupling surface”). The period and/or duty cycle of the grating can be controlled to modify the effective refractive index profile in the direction away from the coupling region so as to reduce the effective refractive index from the relatively high value useful in multi-wavelength coupling to the lower value associated with maintaining confinement of the optical signals within the surface waveguide structure, thus reducing reflections along the transition region.

An apparatus and method for controlling bias in an optical modulator is disclosed. The method is particularly applicable to controlling multi-wavelength modulators and wavelength-tunable transmitters. At a calibration stage, a desired optical performance of the modulator is achieved, and an amplitude of a peak-to-peak variation of the output optical signal at a pre-determined amount of dither is stored in a memory as a reference. At operating stage, a controller of the optical modulator adjusts a bias voltage of the modulator until the measured peak-to-peak optical signal variation matches the reference value stored at the calibration stage. For multi-wavelength modulators and tunable transmitters, the calibration is repeated at each wavelength, and corresponding peak-to-peak optical signal variations are stored in the memory.