283results about How to "Reduce coherence" patented technology

A system and a method for creating a stable and reproducible interface of an optical sensor system for measuring blood glucose levels in biological tissue include a dual wedge prism sensor attached to a disposable optic that comprises a focusing lens and an optical window. The disposable optic adheres to the skin to allow a patient to take multiple readings or scans at the same location. The disposable optic includes a Petzval surface placed flush against the skin to maintain the focal point of the optical beam on the surface of the skin. Additionally, the integrity of the sensor signal is maximized by varying the rotation rates of the dual wedge prisms over time in relation to the depth scan rate of the sensor. Optimally, a medium may be injected between the disposable and the skin to match the respective refractive indices and optimize the signal collection of the sensor.

Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code. The structure and dynamics of sub-cellular constituents cannot be currently studied in their native state using the existing methods and technologies including, for example, x-ray and neutron scattering. In contrast, light based techniques with nanometer resolution enable the cellular machinery to be studied in its native state. Thus, preferred embodiments of the present invention include systems based on principles of interferometry and / or phase measurements and are used to study cellular physiology. These systems include principles of low coherence interferometry (LCI) using optical interferometers to measure phase, or light scattering spectroscopy (LSS) wherein interference within the cellular components themselves is used, or in the alternative the principles of LCI and LSS can be combined to result in systems of the present invention.

This invention relates to a method and system for the radio location of CDMA and non-CDMA enabled transmitters within a reception zone. The invention exploits the superposition of antenna patterns that create complex and asymmetrical interference structures at very small scales. By randomly distributing a random antenna array of M elements across a two or three-dimensional surface, fine scale interference structures on the scale of ¼ the carrier wavelength are generated. Once the minimum number of antennas are placed, additional antennas will not improve the resolution. Such interference structures when sampled at ⅛ the carrier wavelength or greater yields unique spatial patterns with respect to a given antenna array geometry and transmitter location. The invention incorporates signature recognition (matching) and orthogonal sub-space projection estimators to derive location estimates of a radio transmitter.

A laser light source apparatus includes a first laser array light source that emits first-wavelength light, and a second laser array light source that emits second-wavelength light, the second wavelength being different from the first wavelength. The first laser array light source includes a first fundamental wave laser array that produces first fundamental wave light having a first original wavelength, and a first wavelength conversion element that wavelength-converts the first fundamental wave light into the first-wavelength light. The second laser array light source includes a second fundamental wave laser array that produces second fundamental wave light having a second original wavelength different from the first original wavelength, and a second wavelength conversion element that wavelength-converts the second fundamental wave light into the second-wavelength light.

Described herein are display devices that provide projection-type video output and use diode lasers to generate light. For example, one set of diode lasers may produce red light, while a second set produces blue light. Optics are employed to expand laser light from its small generated or transmitted flux area to a size suitable for transmission onto the optical modulation device. Another aspect of the invention relates to a redundant laser set to generate light. A redundant laser set includes more lasers than that needed to produce the desired amount of light.

A projection video display includes at least one laser for delivering a light beam. The display includes a beam homogenizer and a condenser lens. A scanning arrangement is provided for scanning the light in beam in a particular pattern over the condenser lens in a manner that effectively increases the beam divergence. The scanned beam is homogenized by a beam homogenizer and a spatial light modulator is arranged to receive the homogenized scanned light beam and spatially modulate the beam in accordance with a component of an image to be displayed. Projection optics are projecting the homogenized scanned light beam onto a screen. The scanning provides that the homogenized scanned light beam at the screen has a coherence radius less than the original coherence radius of the beam. The reduced coherence radius contributes to minimizing speckle contrast in the image displayed on the screen. The screen includes one or more features providing a further contribution to minimizing speckle contrast in the displayed image. In one example, the screen includes a transparent cell containing a liquid having light scattering particles in suspension.

This disclosure concerns methods and apparatus for interferometric spectroscopic measurements of particles with higher signal to noise ratio utilizing an infrared light beam that is split into two beams. At least one beam may be directed through a measurement volume containing a sample including a medium. The two beams may then be recombined and measured by a detector. The phase differential between the two beams may be selected to provide destructive interference when no particle is present in the measurement volume. A sample including medium with a particle is introduced to the measurement volume and the detected change resulting from at least one of resonant mid-infrared absorption, non-resonant mid-infrared absorption, and scattering by the particle may be used to determine a property of the particle. A wide range of properties of particles may be determined, wherein the particles may include living cells.

Disclosed is a method and apparatus for inspecting defects of patterns of a sample at high speed and with high sensitivity while damage of the sample arising from high-power pulsed light is reduced. Light emitted from a pulsed laser light source is transmitted through a pseudo continuous-wave forming optical system having an optical system capable of reducing energy per pulse and yet maintaining the entire amount of light of the pulsed light, a beam formation optical system, and a coherence reduction optical system, and a beam deflected by a deformation illumination optical system is made to reflect on a PBS to be irradiated on a wafer. The apparatus is configured so that the diffracted light from the wafer is focused by an objective lens, transmitted through light modulation units, focused to form a plurality of images on a plurality of image sensors in a visual-field divided parallel detection unit 12, and then defects are detected by a signal processing unit.

A light source device includes plural light-emitting elements that emit lights, a wavelength selection element that has plural light selection areas in which wavelength selection is performed for the lights emitted from the plural light-emitting elements, respectively, and selectively reflects a part of the lights emitted from the plural light-emitting elements, a state detecting unit that detects states of the plural light selection areas of the wavelength selection element, and a state changing unit that changes, according to the states of the plural light selection areas detected by the state detecting unit, the states of the light selection areas of the wavelength selection element to make wavelengths of the lights selected in the plural light selection areas different from one another.

This invention relates to a method and system for the radio location of CDMA and non-CDMA enabled transmitters within a reception zone. The invention exploits the superposition of antenna patterns that create complex and asymmetrical interference structures at very small scales. By randomly distributing a random antenna array of M elements across a two or three-dimensional surface, fine scale interference structures on the scale of ¼ the carrier wavelength are generated. Once the minimum number of antennas are placed, additional antennas will not improve the resolution. Such interference structures when sampled at 1 / 8 the carrier wavelength or greater yields unique spatial patterns with respect to a given antenna array geometry and transmitter location. The invention incorporates signature recognition (matching) and orthogonal sub-space projection estimators to derive location estimates of a radio transmitter.

The invention relates to a laser-based light source comprising a laser device (1) adapted for generating laser light of a predetermined laser wavelength and emitting this laser light as a laser beam; a light-conversion device (2) for converting at least part of the laser light into converted light; a laser-output sensor (7) for determining a laser-output signal proportional to the output of laser light emitted by the laser device (1); a converted-light sensor (6) for determining a converted-light signal proportional to the output of converted light emitted by the light-conversion device (7); and a controller (9) which is adapted for receiving the laser-output signal and the converted-light signal, for determining a safe-to-operate parameter, based on the laser-output signal and the converted-light signal, and for controlling the operation of the laser-based light source, based on a comparison of the safe-to-operate parameter with a at least one predefined threshold. In this way, a laser-based light source is proposed which enables reliable eye-safety in an easy way.

A projection video display includes at least one laser for delivering a light beam. The display includes a beam homogenizer and a condenser lens. A scanning arrangement is provided for scanning the light in beam in a particular pattern over the condenser lens in a manner that effectively increases the beam divergence. The scanned beam is homogenized by a beam homogenizer and a spatial light modulator is arranged to receive the homogenized scanned light beam and spatially modulate the beam in accordance with a component of an image to be displayed. Projection optics are projecting the homogenized scanned light beam onto a screen. The scanning provides that the homogenized scanned light beam at the screen has a coherence radius less than the original coherence radius of the beam. The reduced coherence radius contributes to minimizing speckle contrast in the image displayed on the screen. The screen includes one or more features providing a further contribution to minimizing speckle contrast in the displayed image. In one example, the screen includes a transparent cell containing a liquid having light scattering particles in suspension.

Described herein are display devices that provide projection-type video output and use diode lasers to generate light. For example, one set of diode lasers may produce red light, while a second set produces blue light. Optics are employed to expand laser light from its small generated or transmitted flux area to a size suitable for transmission onto the optical modulation device. Another aspect of the invention relates to a redundant laser set to generate light. A redundant laser set includes more lasers than that needed to produce the desired amount of light.

Preferred embodiments of the present invention are directed to systems for phase measurement which address the problem of phase noise using combinations of a number of strategies including, but not limited to, common-path interferometry, phase referencing, active stabilization and differential measurement. Embodiment are directed to optical devices for imaging small biological objects with light. These embodiments can be applied to the fields of, for example, cellular physiology and neuroscience. These preferred embodiments are based on principles of phase measurements and imaging technologies. The scientific motivation for using phase measurements and imaging technologies is derived from, for example, cellular biology at the sub-micron level which can include, without limitation, imaging origins of dysplasia, cellular communication, neuronal transmission and implementation of the genetic code. The structure and dynamics of sub-cellular constituents cannot be currently studied in their native state using the existing methods and technologies including, for example, x-ray and neutron scattering. In contrast, light based techniques with nanometer resolution enable the cellular machinery to be studied in its native state. Thus, preferred embodiments of the present invention include systems based on principles of interferometry and / or phase measurements and are used to study cellular physiology. These systems include principles of low coherence interferometry (LCI) using optical interferometers to measure phase, or light scattering spectroscopy (LSS) wherein interference within the cellular components themselves is used, or in the alternative the principles of LCI and LSS can be combined to result in systems of the present invention.

Described herein are display devices that provide projection-type video output and use lasers to generate light. To reduce any speckle effects for a projected image cast by a projector onto of a non-specular surface, the present invention decreases coherence of the laser-generated light. Coherence reduction is accomplished by introducing a coherence diffuser in a light path of the laser light. Arranging the coherence diffuser in an unfocused light beam reduces both temporal and spatial coherence in the light. Arranging the rotating diffuser at the focus of a beam reduces only the temporal coherence while maintaining the spatial coherence.

An optical receiver demodulates optical orthogonal frequency division multiplexed signals and generates a number of subcarrier reference signals, each for demodulating a frequency channel of the frequency division multiplexed signals. It compensates for degradations in the generated reference signals by averaging a number of estimates derived from different inputs to make the references more resilient to degradations. It can encompass time averaging to compensate for amplification noise, and frequency averaging of phase drift estimation to compensate for phase drift caused by reduced source coherence. It can enable longer system reach and / or increased optical power margins by means of better system resilience to amplification noise and reduced source coherence. The bit error rate can be reduced, and / or the capacity can be increased by increasing bit rate or introducing more frequency channels.