Hewlett-packard Company

Forster Energy LLC

Agilent Technologies, Inc.

Lumileds Lighting U.s., LLC

Gregory M Cutler

Andreas G Weber

Ji Li

Norman L Swenson

James F Coward

Peter H Chang

Laurence J Newell

Ting K Yee

James B Williamson

Michael W Rowan

Slava Yazhgur

William R Trutna, Jr

Matthew Charles Bashaw

Shin-Sheng Tarng

Matthew C Bradshaw

Gerd O Muller

Regina B Muller-Mach

Chin-Sheng Tarng

A transmitter subsystem generates an optical signal which contains multiple subbands of information. The subbands have different polarizations. For example, in one approach, two or more optical transmitters generate optical signals which have different polarizations. An optical combiner optically combines the optical signals into a composite optical signal for transmission across an optical fiber. In another aspect, each optical transmitter generates an optical signal containing both a lower optical sideband and an upper optical sideband (i.e., a double sideband optical signal). An optical filter selects the upper optical sideband of one optical signal and the lower optical sideband of another optical signal to produce a composite optical signal.

Optical communications using multiplexed single sideband transmission and heterodyne detection

A transmitter subsystem generates an optical signal which contains multiple subbands of information. The subbands have different polarization. For example, in one approach, two or more optical transmitters generate optical signals which have different polarization. An optical combiner optically combines the optical signals into a composite optical signal for transmission across an optical fiber. In another aspect, each optical transmitter generates an optical signal containing both a lower optical sideband and an upper optical sideband (i.e., a double sideband optical signal). An optical filter selects the upper optical sideband of one optical signal and the lower optical sideband of another optical signal to produce a composite optical signal.

A light emitting device comprises a light emitting diode that emits primary light and a SrGa S :Eu phosphor material capable of absorbing at least a portion of the primary light and emitting secondary light. The secondary light includes a wavelength longer than a wavelength of the primary light.

Green phosphor converted light emitting diode

An illumination source for use in projectors and the like. The illumination source includes a light source that generates a two-dimensional emission pattern having a light intensity that varies as a function of position in the emission pattern. A collector collects the light from the light source and illuminates an exit aperture therewith. The illuminated exit aperture has a two-dimensional emission pattern with a light intensity that varies as a function of position in a manner that is more uniform as a function of position than the emission pattern of the light source. An imaging optical element images the exit aperture onto a surface. The collector is preferably a compound parabolic concentrator or a compound elliptical concentrator. In one embodiment of the invention, a partially reflecting film is placed between the exit aperture and the imaging optical element. The partially reflecting film reflects light of a first polarization state back into the collector and transmits light of the orthogonal polarization state. In another embodiment of the invention, a quarter wave plate is introduced between the exit aperture and the partially reflecting film to further increase the radiance of the source.

Solid state based illumination source for a projection display

The optical scanner comprises a light source, an image sensor, a planar array of elongate optical waveguides, and input and output coupling optics for communicating light to and from the image transmission optics. The light source is adapted to direct light toward and reflect light from an object to be scanned. The planar array of elongate optical waveguides is formed in a substrate. Each of the waveguides include an input end and an output end and can be tapered along the length of the waveguide. The input optics disposed between the object and the waveguide array can include tubes, single lenses per waveguide, larger lenses per cluster of waveguides, a GRIN lens array or comparable mirror systems for directing light reflected from the object to be scanned to the input ends of the waveguides. The output optics disposed between the waveguide array and the image sensor can include lenses or mirror systems similar to that used for the input coupling optics.

Waveguide array document scanner

Picture signals representing a stored image stored in an image storage medium are generated. A stimulation beam having a monotonic non-uniform intensity distribution and a sensor array including a rectangular array of pixels each generating an image signal are provided. Each pixel generates in response to light. An image of an object area of the stored image is formed on the sensor array to define in the object area a fixel corresponding to each pixel of the sensor array. The object area is a small fraction of the area of the stored image. The stored image is stimulated by forming a stimulation spot substantially centered in the object area of the stored image using the stimulation beam. The stored image is scanned with the object area and the stimulation spot. This defines fixels in the stored image and generates a picture signal for each fixel. The picture signal for each fixel represents the accumulation of light emitted by the fixel in response to the stimulation spot. In scanning the stored image, the position of the object area and stimulation spot is successively changed relative to the stored image along a first axis to scan a slice of the stored image. Successive slices of the stored image are scanned along a second axis, substantially orthogonal to the first axis. At each position of the object area in the stored image, the sensor array is controlled to generate an image signal in response to the light emitted by each fixel in the object area. Finally, for each fixel in the stored image, all the image signals generated by the sensor array are accumulated to generate the picture signal for the fixel.

High speed scanner for reading latent images in storage phosphors

The present invention is a composition for use in constructing a photosensitive film for recording color images. The preferred composition includes first, second, and third particle types. Each particle type comprises a crystalline base material having a trap dopant and a color dopant deposited therein. Each of the color dopants has a different activation energy for releasing electrons into the conduction/communication band of the crystalline base material. This results in a different spectral sensitivity for each dopant, and, hence for each particle type. In addition, each of the trap dopants has a different activation energy for releasing trapped electrons into the conduction/communication band of the crystalline base material. This enables the recorded color image to be read out one color at a time, which avoids color distortion. The invention also provides a photosensitive film for recording a color image. The film comprises a backing material having a plurality of depressions therein. The depressions are filled with a photosensitive material that includes first, second, and third particle types. Each particle type comprises a crystalline base material doped with atoms of a trap dopant and a color dopant. Each color dopant has a different spectral sensitivity, and each trap dopant has a different activation energy for releasing trapped electrons into the conduction/communication band of the crystalline base material.

Phosphor film composition for use in image capture

The present invention concerns an interferometer for measuring wavelengths using a rotating periscope and a laser of known wavelength. The rotating periscope uses parallel reflectors mounted on a rotating platform. A beam splitter splits an input beam into two optical paths which reflect off the rotating periscope and back reflectors so that the paths will have a path length difference. The beam splitter splits a reference beam from the laser with known wavelength into two reference optical paths which counter-propagate the input beam's optical paths. The light is recombined in a beam splitter to form an interference signal and a reference interference signal so that the input beam's wavelength can be determined.

Angular michelson interferometer and optical wavemeter based on a

An improved frequency locking circuit suitable for indirectly locking an optical frequency f.sub.0 to a radio frequency f.sub.1 or of locking the radio frequency to the optical frequency. A beam of optical frequency f.sub.0 is modulated by a compound signal which is the sum of a signal at frequency f.sub.2 and an FM subcarrier at frequency f.sub.1 that is phase modulated at frequency f.sub.3 to produce a phase modulated beam. The phase modulated beam is filtered by a filter having a transfer function having a characteristic frequency f.sub.f. A pair of control signals are generated that are proportional respectively to the amplitudes of two components of the filtered signal at frequencies f.sub.2, f.sub.3. These control signals are separately used in a pair of servo loops to separately establish fixed values of f.sub.0 /f.sub.f and f.sub.1 /f.sub.f. By using an optical cavity of the filter, the frequency locking circuit may be used for measuring the refractive index of a gas. The circuit may also be used for calibrating a multi-mode filter.

Frequency locking device

A digital integrating mixer is described including a bandpass filter for filtering an input signal, a comparator for comparing the filtered signal to a reference signal to provide an output which may be of one of two values. A cascaded string of D flip-flops samples the comparator output at predetermined times to provide a first and second type of sample. The time interval between any two samples of the same type is an integral multiple of the cycles of the input signal. The time interval between any two samples of different types is different from an integral multiple of a cycle of the input signal. The mixer also includes a counter which counts up when the sample is of the first value and counts down when the sample is of the second value, when the sample is of the first type, and counts in the opposite direction when the sample is of the second type. If the string of D flip-flops samples approximately an equal number of the first and second types of samples, DC offset in the mixer is reduced. In addition a two channel digital integrating mixer with an analogous structure is disclosed. In the two channel mixer, the string of D flip-flops may also be used to sample the comparator output at predetermined times to provide four types of samples where the time interval between any two samples of the same type is an integral multiple of a cycle of the input signal. The time interval between any first type of sample and any second type of sample is different from an integral multiple of a cycle of the input signal; the same is true between the third and fourth types of samples. The time between any first and second type of sample and any third and fourth type of sample is other than a multiple of a half cycle of the input signal. A first counter is used to count in response to the first or second types of samples and the second in response to the third or fourth types of samples in the same manner as in the single channel mixer. If the string of D flip-flops samples approximately equal number of first and second types of samples and approximately an equal number of third and fourth types of samples, DC offset in the two channel mixer is reduced.

Digital integtrating mixer

Circuit imperfections in phase modulators will introduce offsets in the servo error signals in frequency locking circuits. Such offsets will also cause a frequency offset. The frequency offset is first reduced by reducing or removing amplitude modulation at the modulating frequency in the modulated carrier signal. In the preferred embodiment, this is accomplished by a coupled servo which includes a matrix loop filter. After the amplitude modulation at the modulating frequency has been removed, sideband imbalance can be corrected by amplitude modulating the modulating signal so that the offset caused by sideband imbalance is reduced or eliminated. This will be the case provided that the integral of at least the third power of the amplitude modulation vanishes.

Frequency locking circuit with sideband imbalance correction

A wavemeter/frequency locking technique suitable for indirectly locking an optical frequency f.sub.0 to a radio frequency f.sub.1 or for locking the radio frequency to the optical frequency. A beam of optical frequency f.sub.0 is phase modulated by a signal of average frequency f.sub.1 that is itself modulated at frequency f.sub.2. The modulated beam is passed through a filter to a detector to produce a detector output signal that has components at linear integral sums of f.sub.1 and f.sub.2. A pair of control signals are generated that are proportional to the amplitude of two of the components of the detector output signal. These control signals are separately used in a pair of servo loops to separately establish fixed values of f.sub.0 /f.sub.f and f.sub.1 /f.sub.f, where f.sub.f is a characteristic frequency of the filter. A method is presented for stepping the value of f.sub.0 /f.sub.f to another value and measuring f.sub.1 /f.sub.2 at each of these values, thereby enabling the value of f.sub.0 to be determined.

Growing community of inventors

Cupertino, CA, United States of America

Gregory M Cutler