Patents by Inventor Saurav Das
Saurav Das has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9042234Abstract: A network may include a core region having routers and peripheral regions coupled to the core regions. Switches controlled by a controller may be interposed between the routers. The controller may maintain network topology information of the network. A path computation module may identify forwarding paths between the network routers based on the network topology information and other information such as network traffic history, current network traffic conditions, future network traffic forecasts, or other desired network information. The controller may control the switches to implement the identified forwarding paths. The controller may detect network topology changes and update forwarding paths based on the detected network topology changes. The controller may determine weights of path segments of the network topology. A routing module may provide the path segment weights to the routers using a network protocol.Type: GrantFiled: October 31, 2012Date of Patent: May 26, 2015Assignee: Big Switch Networks, Inc.Inventors: Christopher D. Liljenstolpe, Saurav Das
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Patent number: 7840104Abstract: A multiplexing AWG device capable of producing an ultra-wideband, low ripple, flat-top signal is presented. The AWG device includes an AWG unit and a two-section waveguide coupled to the AWG unit. The two-section waveguide has a first section and a second section. The first section produces a signal having a double-peak field profile and has a first input end and a first output end. The second section reduces the phase variation of the signal having the double-peak field profile exiting the first section. The second section has a second input end that is coupled to the first output end. For example, the first section may be a parabolic tapered waveguide and the second section may be a rectangular waveguide.Type: GrantFiled: July 13, 2007Date of Patent: November 23, 2010Assignee: Enablence USA Components, Inc.Inventors: Saurav Das, Boris Grek, Wenhua Lin
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Patent number: 7639908Abstract: The invention is a data transmission device that includes: an input Free Propagation Region (FPR) receiving a multi-wavelength signal and a single-wavelength signal, and two sets of arrayed waveguides coupled to the input FPR to carry the multi-wavelength signal and the single-wavelength signal, respectively. The arrayed waveguides demultiplex the multi-wavelength signal and create copies of the single-wavelength signal. The output plane of an output FPR receives the demultiplexed wavelengths and the copies of the single-wavelength signal such that one of the demultiplexed wavelengths and one of the copies of the single-wavelength signal focus onto the same position on the output plane. The device allows data (e.g., video stream) to be broadcast to all subscribers in a Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) architecture.Type: GrantFiled: January 23, 2008Date of Patent: December 29, 2009Assignee: Enablence USA Components, Inc.Inventors: Saurav Das, Boris Grek, Jacob Sun
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Publication number: 20090185806Abstract: The invention is a data transmission device that includes: an input Free Propagation Region (FPR) receiving a multi-wavelength signal and a single-wavelength signal, and two sets of arrayed waveguides coupled to the input FPR to carry the multi-wavelength signal and the single-wavelength signal, respectively. The arrayed waveguides demultiplex the multi-wavelength signal and create copies of the single-wavelength signal. The output plane of an output FPR receives the demultiplexed wavelengths and the copies of the single-wavelength signal such that one of the demultiplexed wavelengths and one of the copies of the single-wavelength signal focus onto the same position on the output plane. The device allows data (e.g., video stream) to be broadcast to all subscribers in a Wavelength-Division-Multiplexed Passive Optical Network (WDM-PON) architecture.Type: ApplicationFiled: January 23, 2008Publication date: July 23, 2009Inventors: Saurav Das, Boris Grek, Jacob Sun
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Publication number: 20090016679Abstract: A multiplexing AWG device capable of producing an ultra-wideband, low ripple, flat-top signal is presented. The AWG device includes an AWG unit and a two-section waveguide coupled to the AWG unit. The two-section waveguide has a first section and a second section. The first section produces a signal having a double-peak field profile and has a first input end and a first output end. The second section reduces the phase variation of the signal having the double-peak field profile exiting the first section. The second section has a second input end that is coupled to the first output end. For example, the first section may be a parabolic tapered waveguide and the second section may be a rectangular waveguide.Type: ApplicationFiled: July 13, 2007Publication date: January 15, 2009Inventors: Saurav Das, Boris Grek, Wenhua Lin
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Patent number: 7440655Abstract: An optical device that includes an input region, an output region, and an arrayed waveguide grating between the input region and the output region is presented. The input region includes a first input waveguide set and a second input waveguide set, and the output region includes a first output waveguide set and a second output waveguide set. The arrayed waveguide grating is shared by the signals that travel from the input region to the output region. The device is capable of simultaneously functioning as a multiplexer and a demultiplexer, thereby reducing the cost and complexity of a dual-function optical device. Where the arrayed waveguide grating is used for multiplexing, the optical device receives demultiplexed input signals and generates a multiplexed signal. Where the arrayed waveguide grating is used for demultiplexing, the optical device receives a multiplexed input signal and generates a set of demultiplexed signals.Type: GrantFiled: September 21, 2005Date of Patent: October 21, 2008Assignee: ANDevices, Inc.Inventors: Boris Grek, Saurav Das
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Patent number: 7403284Abstract: A spectrophotometer capable of high spectral resolution (e.g., in the GHz range) is presented. The spectrophotometer includes a container for holding a sample, an arrayed-waveguide grating coupled to the sample holder, and a detector array coupled to the arrayed-waveguide grating. The arrayed-waveguide grating may be a monolithic chip, and the container may be integrated into the chip. An integrated container may be a microfluidic channel formed through the layers in the chip and positioned in such a way that light is transferable from the microfluidic channel to the waveguides of the arrayed-waveguide grating. The invention is also a method of making the spectrophotometer. The method entails providing an arrayed-waveguide grating having an input end and an output end, coupling a container to the input end, wherein the container is capable of holding a sample, and coupling a detector array to the output end of the arrayed-waveguide grating.Type: GrantFiled: December 16, 2004Date of Patent: July 22, 2008Assignee: ANDevices, Inc.Inventors: Boris Grek, Saurav Das
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Publication number: 20070065076Abstract: An optical device that includes an input region, an output region, and an arrayed waveguide grating between the input region and the output region is presented. The input region includes a first input waveguide set and a second input waveguide set, and the output region includes a first output waveguide set and a second output waveguide set. The arrayed waveguide grating is shared by the signals that travel from the input region to the output region. The device is capable of simultaneously functioning as a multiplexer and a demultiplexer, thereby reducing the cost and complexity of a dual-function optical device. Where the arrayed waveguide grating is used for multiplexing, the optical device receives demultiplexed input signals and generates a multiplexed signal. Where the arrayed waveguide grating is used for demultiplexing, the optical device receives a multiplexed input signal and generates a set of demultiplexed signals.Type: ApplicationFiled: September 21, 2005Publication date: March 22, 2007Inventors: Boris Grek, Saurav Das
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Publication number: 20060132764Abstract: A spectrophotometer capable of high spectral resolution (e.g., in the GHz range) is presented. The spectrophotometer includes a container for holding a sample, an arrayed-waveguide grating coupled to the sample holder, and a detector array coupled to the arrayed-waveguide grating. The arrayed-waveguide grating may be a monolithic chip, and the container may be integrated into the chip. An integrated container may be a microfluidic channel formed through the layers in the chip and positioned in such a way that light is transferable from the microfluidic channel to the waveguides of the arrayed-waveguide grating. The invention is also a method of making the spectrophotometer. The method entails providing an arrayed-waveguide grating having an input end and an output end, coupling a container to the input end, wherein the container is capable of holding a sample, and coupling a detector array to the output end of the arrayed-waveguide grating.Type: ApplicationFiled: December 16, 2004Publication date: June 22, 2006Inventors: Boris Grek, Saurav Das