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Gang He
Gang He, Quebec CA
| Patent application number | Description | Published |
|---|---|---|
| 20100129074 | IN-BAND OPTICAL SIGNAL TO NOISE RATIO DETERMINATION METHOD AND SYSTEM - There is provided a method for determining the in-band noise in agile multichannel Dense Wavelength Division Multiplexing (DWDM) optical systems, where the interchannel noise is not representative of the in-band noise in the optical channel. The method relies on the analysis of two observations of the same input optical signal. In the two observations, the linear relationship between the optical signal contribution and the optical noise contribution (i.e. the observed OSNR) is different, which allows the discrimination of the signal and noise contributions in the input optical signal. In a first approach, the two observations are provided by polarization analysis of the input optical signal. In a second, the input optical signal is obtained using two different integration widths. | 05-27-2010 |
| 20110091206 | IN-BAND OPTICAL NOISE MEASUREMENT USING DIFFERENTIAL POLARIZATION RESPONSE - A method comprises: acquiring, for a number nSOP of varied State-Of-Polarization analysis conditions of the input optical signal, nSOP polarization-analyzed optical spectrum traces; mathematically discriminating said signal contribution from said noise contribution within said optical signal bandwidth using said polarization-analyzed optical spectrum traces, said mathematically discriminating comprising: obtaining a differential polarization response that is related to the optical spectrum of said signal contribution by a constant of proportionality; estimating the constant of proportionality of a differential polarization response to the optical spectrum of said signal contribution; estimating the optical spectrum of said noise contribution from said input optical signal, within said optical signal bandwidth using said constant of proportionality and said differential polarization response; and determining said in-band noise parameter on said input optical signal from the mathematically discriminated noise contribution. | 04-21-2011 |
Gang He, Sunnyvale, CA US
| Patent application number | Description | Published |
|---|---|---|
| 20100147370 | MULTIPLE STACK DEPOSITION FOR EPITAXIAL LIFT OFF - Embodiments of the invention are provided for a thin film stack containing a plurality of epitaxial stacks disposed on a substrate and a method for forming such a thin film stack. In one embodiment, the epitaxial stack contains a first sacrificial layer disposed over the substrate, a first epitaxial film disposed over the first sacrificial layer, a second sacrificial layer disposed over the first epitaxial film, and a second epitaxial film disposed over the second sacrificial layer. The thin film stack may further contain additional epitaxial films disposed over sacrificial layers. Generally, the epitaxial films contain gallium arsenide alloys and the sacrificial layers contain aluminum arsenide alloys. Methods provide the removal of the epitaxial films from the substrate by etching away the sacrificial layers during an epitaxial lift off (ELO) process. The epitaxial films are useful as photovoltaic cells, laser diodes, or other devices or materials. | 06-17-2010 |
| 20100219509 | TILED SUBSTRATES FOR DEPOSITION AND EPITAXIAL LIFT OFF PROCESSES - Embodiments of the invention generally relate to epitaxial lift off (ELO) films and methods for producing such films. Embodiments provide a method to simultaneously and separately grow a plurality of ELO films or stacks on a common support substrate which is tiled with numerous epitaxial growth substrates or surfaces. Thereafter, the ELO films are removed from the epitaxial growth substrates by an etching step during an ELO process. The tiled growth substrate contains the epitaxial growth substrates disposed on the support substrate may be reused to grow further ELO films. In one embodiment, a tiled growth substrate is provided which includes two or more gallium arsenide growth substrates separately disposed on a support substrate having a coefficient of thermal expansion within a range from about 5×10 | 09-02-2010 |
Gang He, Quebec City CA
| Patent application number | Description | Published |
|---|---|---|
| 20090033919 | Estimating Loss of Mechanical Splices Interconnecting Optical Fibers, and Connector Installation Tool - A method of estimating loss of a splice between first and second optical fibers spliced together by a mechanical splice or a mechanical splice-based connector having a portion through which light leaked from the splice can emerge comprises the steps of launching light into the first fiber, collecting light leaked from the portion using a multiplicity of ports, measuring the power level of the collected light and deriving the insertion loss from the measured power level, a predetermined power level and a collection factor C representing a relationship between measured power level, predetermined power level, power level of light in the first fiber, and power level of light coupled into the second fiber previously obtained for the same or similar connecting device. The ports may be angularly spaced about the axis of the connector or splice. The predetermined power level may be obtained by measuring light emerging from the connector but without the second fiber in position. | 02-05-2009 |
| 20090135409 | Optical waveguide rotator mechanism, birefringence-inducing element and polarization control devices employing either or both and methods of using same - A fiber rotator mechanism for rotating a portion of an optical waveguide, specifically an optical fiber, about a longitudinal axis thereof comprises a motor having a tubular rotor through which the fiber extends, in use, and to which the fiber is secured, directly or indirectly. An optical fiber may be secured by means of a device which also compresses the optical fiber to induce a required birefringence, conveniently by means of a spring-loaded clamping device or a ferrule of shape memory material. | 05-28-2009 |
Gang He, Woodinville, WA US
| Patent application number | Description | Published |
|---|---|---|
| 20080222221 | Reducing database fragmentation - Reducing database fragmentation is disclosed. One embodiment includes determining whether the building of an index of data that is to be stored in a database has been initiated and determining whether the size of a sub-range of the index exceeds a predetermined size. A block of data storage space is pre-allocated contiguous to a block of data storage space allocated for the sub-range to accommodate subsequent inserts of data into the sub-range, if it is determined that the sub-range exceeds the predetermined size. | 09-11-2008 |
| 20080235296 | Database management using a file to accumulate changes - Database management is described. A source data structure is copied to create a new data structure. Changes to the source data structure that occur during and after creation of the new data structure are accumulated in a file before they are added to the new data structure. Changes included in the file are subsequently applied to the second data structure. | 09-25-2008 |
| 20080243768 | Executing non-blocking parallel scans - Executing non-blocking parallel scans is disclosed. One embodiment includes determining if one or more threads have completed scanning one or more assigned portions of a first division of the data set. The identified one or more threads are directed to immediately scan the portions of a next division of the data set that are identified as available for scanning, upon completing the scanning of assigned portions of the first division of the data set. The threads are directed to immediately scan portions of the next division of the data set free of a need to wait until other threads complete scanning assigned portions of the first division of the data set. | 10-02-2008 |