496 results about "Wavelength shift" patented technology

A photon energy conversion device uses at least one ultraviolet light emitting diode (UV-LED) with a wavelength shifting medium such as phosphor or quantum dots. The device can be used as a light source, and shaped like incandescent light bulbs, fluorescent tubes, circles or compact fluorescent bulbs.

Exemplary embodiments of the invention provide a system, apparatus, and method of controlling an intensity and spectrum of light emitted from a solid state lighting system. The solid state lighting has a first emitted spectrum at full intensity and at a selected temperature, with a first electrical biasing for the solid state lighting producing a first wavelength shift, and a second electrical biasing for the solid state lighting producing a second, opposing wavelength shift. Exemplary embodiments provide for receiving information designating a selected intensity level or a selected temperature; and providing a combined first electrical biasing and second electrical biasing to the solid state lighting to generate emitted light having the selected intensity level and having a second emitted spectrum within a predetermined variance of the first emitted spectrum over a predetermined range of temperatures.

Shaped glasses have curved surface lenses with spectrally complementary filters disposed thereon. The filters curved surface lenses are configured to compensate for wavelength shifts occurring due to viewing angles and other sources. Complementary images are projected for viewing through projection filters having passbands that pre-shift to compensate for subsequent wavelength shifts. At least one filter may have more than 3 primary passbands. For example, two filters include a first filter having passbands of low blue, high blue, low green, high green, and red, and a second filter having passbands of blue, green, and red. The additional passbands may be utilized to more closely match a color space and white point of a projector in which the filters are used. The shaped glasses and projection filters together may be utilized as a system for projecting and viewing 3D images.

A new optical sensing device containing fiber Bragg gratings, a scanning bandpass filter, an interferometer and multiple photodetectors is disclosed. The present invention also describes a new system and method for fibre Bragg grating (FBG) sensor interrogation and multiplexing. The new system combines a scanning Fabry-Perot (SFP) bandpass filter used to wavelength-multiplex multiple gratings in a single fiber, and an unbalanced Mach-Zehnder fibre interferometer made with a 3x3 coupler to detect strain-induced wavelength shifts. A passive technique for interferometer drift compensation using non-sensing FBGs is included in the system. A complete prototype system interrogates four gratings in a single fiber at a Nyquist sampling rate up to 10 kHz, with a noise floor measured near 4 nepsi Hz-½ above 0.1 Hz. The inclusion of the interferometer drift compensation technique is shown to make quasi-static measurements feasible.

A holographic recording and reconstructing apparatus includes a light source having a variable oscillation wavelength; a temperature sensing unit operable to sense temperature; and a control unit operable to record information about a temperature sensed by the temperature sensing unit on a holographic recording medium during recording, to obtain the information about the temperature from the holographic recording medium and obtain a temperature sensed by the temperature sensing unit during reconstruction, to determine the amount of wavelength shift to counteract the effects of a change in the dimension of the holographic recording medium between recording and reconstruction based on the difference between the temperatures, and to shift the oscillation wavelength of the light source by the determined amount.

Shaped glasses have curved surface lenses and spectrally complementary filters disposed on the curved surface lenses configured to compensate for wavelength shifts occurring due to viewing angles and other sources. The spectrally complementary filters include guard bands to prevent crosstalk between spectrally complementary portions of a 3D image viewed through the shaped glasses. In one embodiment, the spectrally complementary filters are disposed on the curved lenses with increasing layer thickness towards edges of the lenses. The projected complementary images may also be pre-shifted to compensate for subsequent wavelength shifts occurring while viewing the images.

A lighting apparatus that provides general lighting in a region or area intended to be occupied by a person includes a source of light of a first spectral characteristic of sufficient light intensity for the lighting application as well as a reflector or a diffusely reflective chamber or cavity having a transmissive optical passage. An exemplary lighting fixture of the type disclosed herein also includes a liquid containing quantum dots. Various containers, locations and positions for the liquid are disclosed. The quantum dots provide a wavelength shift of at least some light to produce a desired second color characteristic in the light output.

According to embodiments of the present invention, a distributed pressure and shear stress sensor includes a flexible substrate, such as PDMS, with a waveguide formed thereon. Along the waveguide path are several Bragg gratings. Each Bragg grating has a characteristic Bragg wavelength that shifts in response to an applied load due to elongation/compression of the grating. The wavelength shifts are monitored using a single input and a single output for the waveguide to determine the amount of applied pressure on the gratings. To measure shear stress, two flexible substrates with the waveguide and Bragg gratings are placed on top of each other such that the waveguides and gratings are perpendicular to each other. To fabricate the distributive pressure and shear sensor, a unique micro-molding technique is used wherein gratings are stamped into PDMS, for example.

Exemplary embodiments of the invention provide a system, apparatus, and method of controlling an intensity and spectrum of light emitted from a solid state lighting system. The solid state lighting has a first emitted spectrum at full intensity and at a selected temperature, with a first electrical biasing for the solid state lighting producing a first wavelength shift, and a second electrical biasing for the solid state lighting producing a second, opposing wavelength shift. Exemplary embodiments provide for receiving information designating a selected intensity level or a selected temperature; and providing a combined first electrical biasing and second electrical biasing to the solid state lighting to generate emitted light having the selected intensity level and having a second emitted spectrum within a predetermined variance of the first emitted spectrum over a predetermined range of temperatures.

Apparatus and method for amplifying laser signals using segments of fibers of differing core diameters and/or differing cladding diameters to suppress amplified spontaneous emission and non-linear effects such as four-wave mixing (FWM), self-phase modulation, and stimulated Brillouin and/or Raman scattering (SBS/SRS). In some embodiments, different core sizes have different sideband spacings (spacing between the desired signal and wavelength-shifted lobes). Changing core sizes and providing phase mismatches prevent buildup of non-linear effects. Some embodiments further include a bandpass filter to remove signal other than the desired signal wavelength and/or a time gate to remove signal at times other than during the desired signal pulse. Some embodiments include photonic-crystal structures to define the core for the signal and/or the inner cladding for the pump. Some embodiments include an inner glass cladding to confine the signal in the core and an outer glass cladding to confine pump light in the inner cladding.

A device contains at least one wavelength-tunable multilayer interference reflector controlled by an applied voltage and at least one cavity. The stopband edge wavelength of the wavelength-tunable multilayer interference reflector is preferably electrooptically tuned using the quantum confined Stark effect in the vicinity of the cavity mode (or a composite cavity mode), resulting in a modulated transmittance of the multilayer interference reflector. A light-emitting medium is preferably introduced in the cavity or in one of the cavities permitting the optoelectronic device to work as an intensity-modulated light-emitting diode or diode laser by applying an injection current. The device preferably contains at least three electric contacts to apply forward or reverse bias and may operate as a vertical cavity surface emitting light-emitter or modulator or as an edge-emitting light emitter or modulator. Using a multilayer interference reflector containing tunable section allows also obtaining a wavelength-tunable laser or a wavelength-tunable resonant cavity photodetector in the case where the optical field profile in the active cavity or cavities is affected by the stopband wavelength shift. Adding additional modulator sections enables applications in semiconductor optical amplifiers, frequency converters or lock-in optical amplifiers.

A lidar system capable of remotely identifying calibrated absolute aerosol backscatter coefficients of atmospheric aerosol particles by transmitting a beam of light and spectrally separating the intensity of Rayleigh and Mie backscattering is disclosed. The transmitter features high pulse energy to generate sufficient Rayleigh backscattering, enabling atmospheric scanning in a timely manner. The transmitter employs a seeded Nd:YAG laser and a seeded stimulated Raman scattering wavelength shifter to achieve narrow bandwidth, eye-safe laser pulses. The receiver employs a telescope, collimating lens, beam splitter, molecular absorption filter, focusing lenses, and avalanche photodiodes. Mie backscattering is blocked by the molecular absorption filter to provide a Rayleigh signal, which is used with knowledge of atmospheric density to calibrate the Mie signal. The system is intended for atmospheric research and aerosol monitoring applications where calibrated Mie scattering intensity is necessary to measure the optical depths of aerosol structures such as plumes, clouds, and layers.

The invention discloses an optical fiber distributed multi-point methane real-time monitor based on the light wave modulation spectrometry and the monitoring method, a semiconductor DFB laser, an optical fiber splitter, a gas calibration pond, a laser control circuit board, a signal generative circuit board, a lock-in amplified board, a data acquisition card, a control module, a multi-channel analog signal selection switch and a driving circuit are arranged in the main case of the monitor, the main case is connected with miniature optical sensors in various underground detection optical path through dingle mode fibers. The wavelength modulation of a gas laser absorption spectrum is realized by a low frequency scanning signal and a high frequency modulation signal generated by a signal generative circuit. The laser wavelength shift is carried out adaptive adjustment by the built-in gas calibration pond so as to realize the locking of a methane absorption line. The distributed multi-point methane concentration monitoring in the underground coal mine is realized by the switching of the multi-channel analog signal selection switch.

A method and apparatus for monitoring changes in temperature or strain, using fiber Bragg gratings (FBG). The Method and apparatus is advantageously useful for the measurement under harsh conditions, such as by combustion turbines. The invention uses the wavelength shift which is caused by temperature or strain changes at the FBG and the changing of the refraction index of the fiber.

Disclosed are a nanoparticle-doped porous bead with a highly enhanced photoluminescence without wavelength shift and improved durability, and a fabrication method thereof, the nanoparticle-doped porous bead comprising porous beads, and nanoparticles radially bonded onto homocentric spheres of the porous beads by an electrostatic attractive force, the homocentric sphere located inside the porous bead near a surface thereof, wherein the nanoparticles are photoluminescent nanoparticles or mixed nanoparticles of photoluminescent nanoparticles and another nanoparticles, wherein the another nanoparticle is one or more than two mixed, selected from a group consisting of magnetic nanoparticle, metallic nanoparticle and metal oxide nanoparticle.

A spectral characteristic measuring apparatus is provided with a memory and a CPU. The memory stores a spectral profile output from a sample light sensor array when light from a lamp is received, and a plurality of spectral profiles to be output from the sensor array at each displaced position in the case where a light separator is displaced relative to a grating member of the sensor array at a certain pitch stepwise in a wavelength diffusing direction. The CPU controls the lamp to emit light in a state that a white plate for calibration is disposed as a sample, compares a spectral profile output from the sensor array for correction with each spectral profile stored in the memory, and sets a displacement amount corresponding to the spectral profile that is most approximate to the corrective spectral profile as a wavelength shift correction amount.

A compact sensor for detecting the presence of biological or chemical species includes a microdisk laser and a wavelength shift detector. The microdisk laser is coated with a biological or chemical recognition element, which binds preferentially with a target analyte. Because the recognition element and the target analyte adhere to the sidewall surface of the microdisk laser, they increase the effective diameter of the laser, which shifts the output wavelength by a detectable amount. The presence of a wavelength shift indicates the presence of the target analyte, and the magnitude of the wavelength shift corresponds to the mass load of the target analyte on the sidewall surface of the microdisk laser.

A detector and methods for inspecting material on the basis of scintillator coupled by wavelength-shifting optical fiber to one or more photo-detectors, with a temporal integration of the photo-detector signal. An unpixelated volume of scintillation medium converts energy of incident penetrating radiation into scintillation light which is extracted from a scintillation light extraction region by a plurality of optical waveguides. This geometry provides for efficient and compact detectors, enabling hitherto unattainable geometries for backscatter detection and for energy discrimination of incident radiation. Additional energy-resolving transmission configurations are enabled as are skew- and misalignment compensation.

An apparatus comprising a laser transmitter having a first side and a second side, a filter coupled to the first side, a detector coupled to the second side, and a temperature controller coupled to the laser transmitter and the detector. Also disclosed is an apparatus comprising at least one processor configured to implement a method comprising receiving a photocurrent of a backward light from a laser, determining a wavelength shift offset between a wavelength of the output light and a filter transmission peak, and adjusting a temperature of the laser to substantially reduce the wavelength shift and align the wavelength of the output light with the filter transmission peak.

An object of disclosed technology is to control lasing wavelengths so that a wavelength shift does not occurs. Another object is to permit wavelengths of a light source for wavelength division multiplexing optical-fiber communication system to be variable in response to an ITU-TS grid. A means for achieving the objects is as follows: locating an etalon in a light path of diode laser light, which is a parallel plane wave changed by a collimator lens; generating a wavelength error signal from a difference between both of divided pieces of light from transmitted light or reflected light; and locking a wavelength of a diode laser device according to the wavelength error signal.