Abstract:
A light fixture, using one or more solid state light emitting elements utilizes a diffusely reflect chamber to provide a virtual source of uniform output light, at an aperture or at a downstream optical processing element of the system. Systems disclosed herein also include a detector, which detects electromagnetic energy from the area intended to be illuminated by the system, of a wavelength absent from a spectrum of the combined light system output. A system controller is responsive to the signal from the detector. The controller typically may control one or more aspects of operation of the solid state light emitter(s), such as system ON-OFF state or system output intensity or color. Examples are also discussed that use the detection signal for other purposes, e.g. to capture data that may be carried on electromagnetic energy of the wavelength sensed by the detector.
Abstract:
Embodiments of the present invention relate to a system and method for practicing spectrophotometry using light emitting nanostructures. Specifically, embodiments of the present invention include a physiologic sensor comprising a sensor body configured for placement adjacent pulsatile tissue of a patient, a first light emitting nanostructure device configured to emit light at a first wavelength through the pulsatile tissue, a second light emitting nanostructure device configured to emit light at a second wavelength through the pulsatile tissue, and a light detector configured to detect the light at the first wavelength and the light at the second wavelength after dispersion through the pulsatile tissue.
Abstract:
The present subject matter relates to methods of high-speed analysis of product samples. Light is directed to a portion of a product under analysis and reflected from or transmitted through the product toward a plurality of optical detectors. Signals from the detectors are compared with a reference signal based on a portion of the illuminating light passing through a reference element to determine characteristics of the product under analysis. The products under analysis may be stationary, moved by an inspection point by conveyor or other means, or may be contained within a container, the container including a window portion through which the product illuminating light may pass.
Abstract:
A system and method are provided for utilizing section contribution characteristic data to achieve accurate measurements by compensating for unwanted phosphor output variations that occur at specific sections of phosphor on a rotating high intensity phosphor point source element. Phosphor grain size, density, blend homogeneity, or illumination gap variations may cause the unwanted variations. Based on the section contribution characteristics, excitation energy compensation may provide a stable output illumination spectrum or computational compensation may correct measurements for effects arising from predictable output illumination spectrum variations. The section contribution characteristic data may comprise section wavelength intensity profile data and/or section efficiency data, in various embodiments. In some embodiments, the sections may be on the order of the size of the phosphor grains and may be characterized and compensated. The sections may include phosphor blends, or distinct phosphor types, in various embodiments.
Abstract:
A frequency comb laser providing large comb spacing is disclosed. At least one embodiment includes a mode locked waveguide laser system. The mode locked waveguide laser includes a laser cavity having a waveguide, and a dispersion control unit (DCU) in the cavity. The DCU imparts an angular dispersion, group-velocity dispersion (GVD) and a spatial chirp to a beam propagating in the cavity. The DCU is capable of producing net GVD in a range from a positive value to a negative value. In some embodiments a tunable fiber frequency comb system configured as an optical frequency synthesizer is provided. In at least one embodiment a low phase noise micro-wave source may be implemented with a fiber comb laser having a comb spacing greater than about 1 GHz. The laser system is suitable for mass-producible fiber comb sources with large comb spacing and low noise. Applications include high-resolution spectroscopy.
Abstract:
A system for determining an analyte concentration in a fluid sample (e.g., glucose) comprises a light source, a detector, and a central processing unit. The detector is adapted to receive spectral information corresponding to light returned from the fluid sample being analyzed and to convert the received spectral information into an electrical signal indicative of the received spectral information. The central processing unit is adapted to compare the electrical signal to an algorithm built upon correlation with the analyte in body fluid. The algorithm is adapted to convert the received spectral information into the analyte concentration in body fluid. Spectral information is delivered from the central processing unit to the light source and used to vary the intensity and timing of the light to improve the accuracy of conversion into analyte concentration.
Abstract:
Systems, methods, and apparatuses of elastic light scattering spectroscopy and low-coherence enhanced backscattering spectroscopy are described here. An apparatus couple-able to a light source and a target object, to facilitate light transmission between the light source and the target object, the apparatus comprises: a probe to emit incident light that is partially coherent obtained from the light source onto the target object and to receive interacted light, the interacted light to be backscattered light from illumination of the incident light on the target object, the probe comprising: a delivery channel having at least one delivery optical fiber with a distal end portion couple-able to the light source and a proximal end portion suited to couple the incident light to the target object, a collection channel having a first collection optical fiber suited to collect substantially co-polarized backscattered light and a second collection optical fiber suited to collect substantially cross-polarized backscattered light.
Abstract:
A sample information input unit obtains spectral reflectances of color patches formed on a medium from a measuring device or storage unit. A media characteristic input unit inputs bi-spectral radiance factors of the medium from the storage unit. A computing unit computes bi-spectral radiance factors of the color patches based on the spectral reflectances of the color patches obtained by the sample information input unit and the bi-spectral radiance factors of the medium input by the media characteristic input unit.
Abstract:
A method of forming an image of a target that comprises illuminating a target with light, maneuvering an optical unit having at least one diffractive element in front of the target through a plurality of positions, capturing, during the maneuvering, a plurality of spectrally encoded frames each from a portion of the light that is scattered from a different of a plurality of overlapping segments along a track traversing an image plane of the target, and combining the plurality of spectrally encoded frames to form a composite multispectral image of at least a portion of said target.
Abstract:
An improved apparatus and method for fluorescence subtraction in Raman spectroscopy, where a narrow band light source and a broad band light source are utilized to stimulate Raman scattering and fluorescence emission from the same subject to produce two Raman/fluorescence spectra. The two light sources, with matched output power, produce similar level of fluorescence emission, yet the Raman scattering signal produced by the broad band light source has much lower spectral intensity than that produced by the narrow band light source. By subtracting the two Raman/fluorescence spectra, the weak Raman signal can be extracted from a strong fluorescence background.