Including Postcompensation Patents (Class 398/208)
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Patent number: 12341565Abstract: A testing system for a modulator includes a radio frequency (RF) generator, an optical power meter, and an electrical power meter. The RF generator is configured to generate and provide a first plurality of RF signals and a second plurality of RF signals, wherein the first plurality of RF signals and the second plurality of RF signals are associated with a plurality of frequencies. The optical power meter is configured to measure an optical power of an output optical signal, which is modulated by the modulator based on the first plurality of RF signals, to facilitate determination of a transmission response measurement of the modulator for each frequency of the plurality of frequencies. The electrical power meter is configured to measure a portion of each RF signal of the second plurality of RF signals to facilitate determination of a reflectance response measurement of the modulator for each frequency.Type: GrantFiled: March 31, 2023Date of Patent: June 24, 2025Assignee: Lumentum Operations LLCInventors: Flavio Dell'Orto, Marco Villa
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Patent number: 12328147Abstract: In one embodiment, an apparatus comprises: a coherent optical receiver front-end circuit to receive an optical signal comprising information and further to receive a local oscillator optical signal, and output an orthogonal electrical signal based on the optical signal; a processing circuit coupled to the coherent optical receiver front-end circuit to receive the orthogonal electrical signal and process the orthogonal electrical signal to generate therefrom sum of squares information; and a non-coherent receiver coupled to the processing circuit to recover the information from the sum of squares information. Other embodiments are described and claimed.Type: GrantFiled: June 22, 2021Date of Patent: June 10, 2025Assignee: Intel CorporationInventors: Christian Malouin, Jin Hong, Wenhua Lin
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Patent number: 12298440Abstract: A method of operating a frequency-modulated continuous wave (FMCW) light detection and ranging (LIDAR) system is provided. The method includes transmitting a beam of co-propagating, cross-polarized light to a target. The method includes receiving return light reflected from the target by at least one detector. The method further includes transforming a polarization state of the beam at a transformation rate faster than a data collection rate from the at least one detector.Type: GrantFiled: September 13, 2023Date of Patent: May 13, 2025Assignee: Aeva, Inc.Inventors: Neal N. Oza, Omer P. Kocaoglu, Behsan Behzadi, Oguzhan Avci, Keith Gagne, Mina Rezk
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Patent number: 12270700Abstract: A method that detects locations of undesired levels of signal loss in DAS systems that use optical fibers. In the method, raw DAS signals are received from an optical fiber of a DAS system with dual photodetector positioned at the end(s) of the optical fiber. Locations on the optical fiber are named “channels” having a certain length on the optical fiber and are numbered according to distances of the channels from the photodetector. The raw DAS signals received from each channel are processed by the dual photodetector to obtain raw DAS statistical data for each channel. The obtained raw DAS statistical data are then reconstructed to produce reconstructed DAS statistical data in which noise has been removed. The reconstructed DAS statistical data form power statistics for each channel. The power statistics is expected to be linearly decreasing with a farther distance of each channel from the photodetector.Type: GrantFiled: December 8, 2022Date of Patent: April 8, 2025Assignee: ASELSAN ELEKTRONIK SANAYI VE TICARET ANONIM SIRKETIInventors: Abdulsamet Dagasan, Mustafa Akur, Muhammet Emre Sahinoglu
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Patent number: 12273148Abstract: Mixing between I and Q components in coherent homodyne optical signals can occur due to phase shifts, e.g. relative to the local oscillator, relative to the other signal components. In some examples, the phase shifts can arise due to thermal expansion of the optical waveguides and/or can include polarization mixing. A descrambler functions to correct for mixing between multiple signal components. The descrambler may be configured to at least partially correct for a phase difference between a first plurality of modulated optical data signals and a first local oscillator reference signal; and a controller may be configured for determining a first correction parameter for at least partially correcting for the phase difference, and for transmitting the first correction parameter to the descrambler. The controller may be configured for determining the first correction parameter from a first pilot signal transmitted with the first plurality of modulated optical data signals.Type: GrantFiled: October 18, 2022Date of Patent: April 8, 2025Assignee: Luminous Computing, Inc.Inventors: Thomas W. Baehr-Jones, Hari Shankar, Florian Bohn
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Patent number: 12272800Abstract: A semiconductor device with reduced power consumption is provided. With three transistors, potentials of two nodes are switched and a voltage is detected. One of a source and a drain of a first transistor is electrically connected to a first terminal. The other of the source and the drain of the first transistor is electrically connected to a non-inverting input of a comparator through a first node. One of a source and a drain of a second transistor is electrically connected to a second terminal. The other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of a third transistor through a second node. The other of the source and the drain of the third transistor is electrically connected to a third terminal. A first capacitor is provided between the first node and the second node. An inverting input of the comparator is electrically connected to a fourth terminal. An output of the comparator is electrically connected to a fifth terminal.Type: GrantFiled: March 16, 2020Date of Patent: April 8, 2025Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takayuki Ikeda, Takeshi Aoki, Munehiro Kozuma, Kei Takahashi, Shunpei Yamazaki
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Patent number: 12199744Abstract: A method includes obtaining information about a next upstream burst transmission. The method also includes determining a set of settings based on the information. The method includes adjusting a physical medium dependent (PMD) module based on the set of settings prior to receiving the next upstream burst transmission.Type: GrantFiled: November 14, 2022Date of Patent: January 14, 2025Assignee: MAXLINEAR, INC.Inventors: Gert Schedelbeck, Thomas Heuken, Franz Josef Schäfer, Rainer Strobel
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Patent number: 12199696Abstract: One example discloses a first near-field device, including: a controller configured to establish a near-field communications link with a second near-field device; wherein the controller is configured to monitor a characteristic of the near-field communications link; wherein the controller is configured to select a first modulation encoding for transmitting a near-field signal if the characteristic is greater than a first characteristic threshold; and wherein the controller is configured to select a second modulation encoding for transmitting the near-field signal if the characteristic is less than the first characteristic threshold but greater than a second characteristic threshold.Type: GrantFiled: June 4, 2021Date of Patent: January 14, 2025Assignee: NXP B.V.Inventors: Liesbeth Gommé, Anthony Kerselaers
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Patent number: 12160269Abstract: A bi-directional and multi-channel optical module incudes an encapsulation casing, a TOSA, a plurality of ROSAs and a plurality of optical folding elements. The TOSA is accommodated in the encapsulation casing. The TOSA includes a light emitting element and a thin film LiNbOx modulator, and a light receiving end of the thin film LiNbOx modulator is optically coupled with the light emitting element. The ROSAs are accommodated in the encapsulation casing. The ROSAs are configured to receive external optical signals propagating into the encapsulation casing. The optical folding elements are optically coupled with a plurality of light propagation ends of the thin film LiNbOx modulator, respectively, for changing a traveling direction of light emitted by the TOSA. Each of the optical folding elements is configured to enable one of the ROSAs share a fiber access terminal with the TOSA.Type: GrantFiled: November 10, 2022Date of Patent: December 3, 2024Assignee: Global Technology Inc.Inventors: Jian-Hong Luo, Dong-Biao Jiang, Fu Chen, Hao Zhou
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Patent number: 12160266Abstract: A system and method for compensating a frequency shift of an optical communication signal may include a tunable receiver laser, a coherent optical receiver that receives the optical communication signal, in which the coherent optical receiver can demodulate the optical communication signal based on an optical output of the tunable receiver laser, a trans-impedance amplifier that receives a demodulated signal from the coherent optical receiver and generates an amplifier output, a laser tracking system that generates a laser tuning signal configured to adjust the optical output of the tunable receiver laser, and a controller including a processor and a memory unit. The memory unit includes instructions that cause the controller to receive the amplifier output, calculate a frequency spectrum of the amplifier output, and determine an offset of a frequency of the optical communication signal from a first frequency of the optical output.Type: GrantFiled: August 9, 2022Date of Patent: December 3, 2024Assignee: CISCO TECHNOLOGY, INC.Inventors: Philippe Jenneve, Bernd Huebner
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Patent number: 12149291Abstract: A coherent receiver includes a receive signal path including i) an input configured to connect a receive signal, ii) one or more signal paths connected to the input and to one or more optical hybrids, and iii) a variable optical attenuator (VOA) in each of the one or more signal paths; and a local oscillator (LO) signal path including i) an input configured to connect to an LO and the one or more optical hybrids, and ii) one or more complementary VOAs located between the input and the one or more optical hybrids, wherein the one or more complementary VOAs are configured to cancel any phase changes from the VOA in each of the one or more signal paths. The VOA in each of the one or more signal paths and the one or more complementary VOAs can be p-i-n junctions.Type: GrantFiled: March 17, 2022Date of Patent: November 19, 2024Assignee: Ciena CorporationInventors: Michel Poulin, Antoine Bois, Tom Luk, François Pelletier, Sean Sebastian O'Keefe
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Patent number: 12149280Abstract: Dynamic error-quantizer tuning systems and methods prevent misconvergence to local minima by using a dynamic quantizer circuit that controls reference voltages of three or more comparators that are independently adjusted to modify the transfer function of the dynamic quantizer circuit. A weighted sum of the comparator outputs is subtracted from the input to form an error signal in a control loop. The ratio of the reference voltages is chosen to reduce or eliminate local minima during a convergence of the control loop and is set to values that minimize a mean squared error signal with respect to discrete modulation states of the input after the convergence of the control loop is complete.Type: GrantFiled: January 20, 2022Date of Patent: November 19, 2024Assignee: Maxim Integrated Products, Inc.Inventor: Charles Razzell
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Patent number: 12109018Abstract: A method and system for calibrating cameras of a monitoring system, the method comprises receiving a plurality of video frames including a wide area view of a patient area from a primary camera of a monitoring subsystem and a view of a region of interest within the patient area from a secondary camera of the monitoring subsystem, detecting a patient event based on an analysis of given ones of the plurality of video frames corresponding to the wide area view, transmitting the given ones of the plurality of video frames and an identification of the patient event to a viewer client device, generating detection-based calibration instructions based on the patient event, wherein the detection-based calibration instructions including control information that controls operation of the secondary camera based on a location of the patient event, and transmitting the detection-based calibration instructions to the monitoring subsystem, wherein the monitoring subsystem configures the secondary camera based on the controlType: GrantFiled: March 8, 2021Date of Patent: October 8, 2024Assignee: CareView Communications, Inc.Inventors: Steven Gail Johnson, Derek del Carpio, Jeffrey C. Lightcap
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Patent number: 12081273Abstract: A coherent optical data receiver having a digital signal processor (DSP) capable of mitigating equalization-enhanced phase noise (EEPN). In an example embodiment, the DSP mitigates EEPN by applying individual phase adjustments to different spectral slices of a digital stream carrying CD-compensated digital samples of the received optical data signal. In different embodiments, the individual phase adjustments can be dynamically selected based on symbol decisions taken prior to EEPN mitigation, based on transmitted pilot symbols, and/or using moving averages computed for different spectral slices. Some embodiments are suitable for handling polarization-division-multiplexed optical data signals. Some embodiments are advantageously capable of producing an effective SNR gain of approximately 1 dB.Type: GrantFiled: May 31, 2022Date of Patent: September 3, 2024Assignee: Nokia Solutions and Networks OyInventors: Vahid Aref, Fred Buchali, Stenio Magalhaes Ranzini
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Patent number: 12081274Abstract: A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.Type: GrantFiled: June 16, 2023Date of Patent: September 3, 2024Assignee: Marvell Asia Pte LtdInventors: Damian Alfonso Morero, Mario A. Castrillion, Ramiro Rogelio Lopez, Cristian Cavenio, Gabriel Infante, Mario Rafael Hueda
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Patent number: 12028109Abstract: A tap-coefficient control circuit sets the tap coefficient converged by the second tap coefficient updater as an initial value of the tap coefficient in the first digital filter which is to be updated by the first tap coefficient updater, arranges the tap coefficients converged by the second tap coefficient updater in descending order of contribution degree to the convergence operation of tap coefficient update in the first tap coefficient updater, judges the tap coefficient not less than upper specified number to be valid and the tap coefficient less than the specified number to be invalid, and sets the tap coefficient of the first digital filter corresponding to the tap coefficient judged to be invalid to zero not to be used in a calculation of the first tap coefficient updater until a next judgment result is made.Type: GrantFiled: May 19, 2021Date of Patent: July 2, 2024Assignee: NTT Innovative Devices CorporationInventors: Tomohiro Takamuku, Mitsuteru Yoshida, Tomoharu Semboku, Tsutomu Takeya
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Patent number: 12028115Abstract: A device for coherent detection of data transported in an optical incoming useful signal. The device includes: a first incoming single-mode optical fibre, injecting the incoming useful signal; a second incoming single-mode optical fibre, injecting an optical signal of optical frequency substantially equal to that of the incoming useful signal, referred to as an oscillation signal, a signal mixer in which one of the signals from the first or second fibre is separated into two signals having orthogonal polarisations, and where the other one of the signals from the first or second fibre is mixed with the two separate signals, producing a mixed signal; a detector of the transported data present in the mixed signal; and an amplitude modulator configured to modulate the oscillation signal before it enters the mixer, the modulation pattern having repetitive pulses of the same interval as a symbol time of the incoming useful signal.Type: GrantFiled: May 27, 2020Date of Patent: July 2, 2024Assignee: ORANGEInventors: Philippe Chanclou, Gaël Simon
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Patent number: 12015441Abstract: Provided are a pulse-matched filter-based packet detection apparatus and method. The packet detection apparatus includes a photoelectric converter for converting an optical wireless communication signal into an electrical signal, an analog-to-digital converter (ADC) for converting the electrical signal into a digital signal, a pulse-matched filter for outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, a correlator for outputting a second correlation representing a correlation between the first correlation and a preamble code, a packet detection signal generator for generating a packet detection signal by comparing the second correlation and a packet detection threshold value, and a demodulator for demodulating the digital signal based on the packet detection signal.Type: GrantFiled: August 31, 2022Date of Patent: June 18, 2024Assignees: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE, GLOBAL LIFI PARTNERS KOREA CO., LTD.Inventors: Jin Doo Jeong, Sang-Kyu Lim
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Patent number: 12009857Abstract: The present invention is directed to communication systems and methods. According to an embodiment, a receiving optical transceiver determines signal quality for signals received from a transmitting optical transceiver. Information related to the signal quality is embedded into back-channel data and sent to the transmitting optical transceiver. The transmitting optical transceiver detects the presence of the back-channel data and adjusts one or more of its operating parameters based on the back-channel data. There are other embodiments as well.Type: GrantFiled: January 14, 2022Date of Patent: June 11, 2024Assignee: MARVELL ASIA PTE LTDInventors: Todd Rope, Radhakrishnan L. Nagarajan
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Patent number: 12009868Abstract: In order to suppress wrong convergence of a filter coefficient without reducing data communication speed, this filter coefficient update amount output device is provided with: a first output unit which outputs a first coefficient update amount derived from a difference between a temporary determination result regarding a processed reception sample value that is the reception sample value on which filter processing by a digital filter has been performed and the processed reception sample value; a second output unit which outputs a second coefficient update amount derived from a gradient with respect to the filter coefficient such that the magnitude of a difference between statistical information on the processed reception sample value during some duration of time, and a set value regarding the statistical information is minimized; and a third output unit which outputs the coefficient update amount derived from the first coefficient update amount and the second coefficient update amount.Type: GrantFiled: September 11, 2020Date of Patent: June 11, 2024Assignee: NEC CORPORATIONInventor: Manabu Arikawa
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Patent number: 11996896Abstract: A method and structure for equalization in coherent optical receivers. Block-based LMS (BLMS) algorithm is one of the many efficient adaptive equalization algorithms used to (i) increase convergence speed and (ii) reduce implementation complexity. Since the computation of the equalizer output and the gradient of the error are obtained using a linear convolution, BLMS can be efficiently implemented in the frequency domain with the constrained frequency-domain BLMS (FBLMS) adaptive algorithm. The present invention introduces a novel reduced complexity constrained FBLMS algorithm. This new approach replaces the two discrete Fourier transform (DFT) stages required to evaluate the DFT of the gradient error, by a simple frequency domain filtering. Implementation complexity can be drastically reduced in comparison to the standard constrained FBLMS. Furthermore, the new approach achieves better performance than that obtained with the unconstrained FBLMS in ultra-high speed coherent optical receivers.Type: GrantFiled: December 21, 2021Date of Patent: May 28, 2024Assignee: Marvell Asia Pte LtdInventors: Mario Rafael Hueda, Nestor D. Campos
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Patent number: 11989945Abstract: The present invention relates to a method for assisting in the detection of elements in an environment, comprising: the acquisition of a first wide-field image of an environment by a first sensor (14A) having a first field of view and a first resolution, the generation of a fused image from first narrow-field images of the environment acquired by a second sensor (14B) having a second field of view strictly less than the first field of view and a second resolution finer than the first resolution, In response to the detection of a difference relating to an element on a second wide-field image acquired by the first sensor (14A), compared to the first wide-field image, the acquisition of a second narrow-field image imaging the difference, and the update the fused image with the second narrow-field image.Type: GrantFiled: March 3, 2021Date of Patent: May 21, 2024Assignee: THALESInventors: Dominique Delacourt, Olivier Cocle, Olivier Verdy, Dominique Bon, Ludovic Perruchot, Alain Le Meur, Frédéric Le Gusquet
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Patent number: 11982552Abstract: Aspects of the present disclosure describe systems, methods. and structures for vibration detection using phase recovered from an optical transponder with coherent detection. Advantageously, our systems, methods, and structures leverage contemporary digital coherent receiver architecture in which various adaptive DSP operations performed to recover transmitted data track optical phase. The phase is extracted at low overhead cost, allowing a digital coherent transponder to perform vibration detection/monitoring as an auxiliary function to data transmission. Demonstration of vibration detection and localization based on the extraction of optical phase from payload-carrying telecommunications signal using a coherent receiver in a bidirectional WDM transmission system is shown and described.Type: GrantFiled: December 7, 2021Date of Patent: May 14, 2024Assignee: NEC CorporationInventors: Ezra Ip, Yue-Kai Huang
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Patent number: 11979694Abstract: An optical and electronic integrated switch includes a network processor that controls the functions of the packet switch, a plurality of optical transceivers having photoelectric conversion functions, and a plurality of optical switches. The optical switches include different types of optical core switch and a plurality of optical-path selection switches. The optical transceivers provided near the processor have a regenerative relay function that regenerates optical signals and turns back the optical signals, and perform optical communication with a communication counterpart via the optical switches. In the optical communication, optical switches of the different types can cooperate to set paths for optical cut-through in which path selection is performed such that inputted optical signals are outputted without the intervention of the processor. This optical cut-through can be effectively performed without imposing a signal processing burden that consumes electric power on the processor.Type: GrantFiled: January 30, 2020Date of Patent: May 7, 2024Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Osamu Moriwaki, Shunichi Soma, Keita Yamaguchi, Kenya Suzuki, Seiki Kuwabara, Tetsuro Inui, Shuto Yamamoto, Seiji Okamoto, Hideki Nishizawa
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Patent number: 11967996Abstract: Embodiments of the present disclosure provide example frequency domain equalization methods, example equalizers, example optical receivers, and example systems. One example method includes obtaining, by an optical receiver, a first complex signal. The first complex signal is a first time domain signal. The first complex signal is obtained based on two channels of mutually independent digital electrical signals. The optical receiver converts the first complex signal into a frequency domain signal, and multiplies the first complex signal in frequency domain by a tap coefficient to obtain a second complex signal. The tap coefficient is used to implement signal compensation for the first complex signal in frequency domain. The optical receiver converts the second complex signal into a second time domain signal, divides the second time domain signal into two channels of real signals, and outputs the two channels of the real signals.Type: GrantFiled: June 17, 2022Date of Patent: April 23, 2024Assignee: Huawei Technologies Co., Ltd.Inventors: Jilong Han, Liangchuan Li
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Patent number: 11901952Abstract: A coherent optical receiver includes equalizer circuitry having a plurality of taps, the equalizer circuitry being configured to receive an input signal and compensate for polarization mode dispersion affecting the input signal to generate a compensated input signal. The coherent optical receiver further includes error evaluation circuitry configured to calculate a determinant of a frequency-domain (FD) coefficient-based matrix using a plurality of tap signals from among the plurality of taps, adjust an error of convergence of the compensated input signal to generate an adjusted input signal, and iteratively adjust the determinant of the FD coefficient-based matrix based on the adjusted input signal to minimize the error of convergence.Type: GrantFiled: August 11, 2022Date of Patent: February 13, 2024Assignee: Marvell Asia Pte Ltd.Inventors: Mario R. Hueda, José Correa, Oscar E. Agazzi
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Patent number: 11901939Abstract: An optical receiver includes an optical amplifier that amplifies a received optical signal containing multiple wavelengths, a monitor circuit that monitors light intensities of the demultiplexed optical signal, a processor, and a memory having information representing a relationship between a total incident light intensity of the optical signal incident onto the optical amplifier and gains of the optical amplifier for the respective wavelengths.Type: GrantFiled: August 29, 2022Date of Patent: February 13, 2024Assignee: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Toshio Ishii, Naoki Kuwata
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Patent number: 11901953Abstract: An optical transmission system, in which an optical transmission apparatus and an optical reception apparatus are provided, includes a coefficient determination unit configured to optimize, based on a reception signal received by the optical reception apparatus, a coefficient to be used to compensate for deterioration according to characteristics of each device configuring a transmission path between the optical transmission apparatus and the optical reception apparatus, and a device characteristic estimation unit configured to estimate the characteristics of each device by using the optimized coefficient.Type: GrantFiled: March 31, 2020Date of Patent: February 13, 2024Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Takeo Sasai, Masanori Nakamura, Asuka Matsushita, Yoshiaki Kisaka
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Patent number: 11888530Abstract: The optical tracking module includes an optical phased array (OPA), an analog drive, an integrated photodetector, and one or more processors. The OPA includes a plurality of array elements, and a plurality of phase shifters. The analog drive is configured to adjust the plurality of phase shifters. The integrated photodetector is configured to receive light from the OPA. The one or more processors is configured to extract signal information of an incoming beam via the OPA, and control an outgoing beam using the analog drive based on the signal information. The OPA, the analog drive, the integrated photodetector and the one or more processors are in an integrated circuit.Type: GrantFiled: March 18, 2022Date of Patent: January 30, 2024Assignee: X DEVELOPMENT LLCInventors: Baris Ibrahim Erkmen, Devin Brinkley, Eric Teller, Thomas Moore, Jean-Laurent Plateau
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Patent number: 11852802Abstract: Disclosed herein are configurations for fiber optic endoscopes employing fixed distal optics and multicore optical fiber.Type: GrantFiled: February 19, 2022Date of Patent: December 26, 2023Inventor: Eric Swanson
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Patent number: 11848710Abstract: This application provides a receiver optical sub-assembly, a bi-directional optical sub-assembly, and an optical network device to improve anti-electromagnetic crosstalk performance of the receiver optical sub-assembly. The receiver optical sub-assembly includes: a photodiode, a trans-impedance amplifier, and a first filter component. The photodiode is configured to convert an optical signal into an electrical signal, a positive electrode of the photodiode is connected to an input terminal of the trans-impedance amplifier, and a negative electrode of the photodiode is configured to connect to a power supply. The trans-impedance amplifier is configured to amplify the electrical signal output by the photodiode, a power terminal of the trans-impedance amplifier is configured to connect to a power supply, and a first ground terminal of the trans-impedance amplifier is configured to connect to an external ground.Type: GrantFiled: December 21, 2021Date of Patent: December 19, 2023Assignee: Huawei Technologies Co., Ltd.Inventors: Rixiang Cao, Yu Xiong, Zelin Wang, Zhe Yu
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Patent number: 11822161Abstract: Provided is a first bias power source that generates a first data bias voltage to be applied to an optical modulation unit for the I component, a second bias power source that generates a second data bias voltage to be applied to an optical modulation unit for the Q component, and a third bias power source that generates a quadrature bias voltage to be applied to an optical phase shifter, a data bias voltage adjustment unit that applies a feedback control to each of the first bias power source and the second bias power source, and a quadrature bias voltage adjustment unit that determines whether or not the quadrature bias voltage is optimal on a basis of a second optical QAM signal generated by an IQ optical modulator, and applies a feedback control to the third bias power source, in which a first optical QAM signal and the second optical QAM signal are generated by the IQ optical modulator but the optical phase difference between an optical electric field EI and an optical electric field EQ differs by ?.Type: GrantFiled: December 11, 2019Date of Patent: November 21, 2023Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATIONInventors: Hiroto Kawakami, Shoichiro Kuwahara, Yoshiaki Kisaka
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Patent number: 11821807Abstract: A transmitter generates a first electrical signal comprising a first low-frequency signal, an empty period, and a pump pulse having a first frequency; and a second electrical signal comprising a second low-frequency signal and at least two probe pulses, each probe pulse having a second frequency that differs from the first frequency. The transmitter modulates first and second optical subcarriers having different polarizations using the first and second electrical signals, respectively. The transmitter generates an optical signal from the first and second optical subcarriers, wherein the first and second low-frequency signals overlap in time, wherein the empty period overlaps in time with one of the probe pulses, and wherein the pump pulse overlaps in time with another one of the probe pulses. The optical signal is detected at a receiver over an optical link, and the receiver uses the optical signal to estimate nonlinear phase shift in the optical link.Type: GrantFiled: July 22, 2021Date of Patent: November 21, 2023Assignee: Ciena CorporationInventors: Rongqing Hui, Maurice O'Sullivan
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Patent number: 11811460Abstract: Real-time systems and methods prevent duplication of independent signal streams in a coherent receiver subject to source separation controlled by multiplicative coefficients under adaptive feedback control. In various embodiments, this is achieved by first obtaining a first set of coefficients associated with a first signal stream and a second set of coefficients associated with a second signal stream. In response to the sets of coefficients satisfying a condition, the first set modified into a set of coefficients that is mutually orthogonal with respect to and replaces the second set of coefficients. The resulting series of coefficient values may then be used to perform source separation of independent signal streams without duplicating independent signal streams.Type: GrantFiled: January 20, 2022Date of Patent: November 7, 2023Assignee: Maxim Integrated Products, Inc.Inventors: Charles Razzell, Edem Ibragimov
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Patent number: 11812205Abstract: A monitoring control unit (22) of an OXC (20d) stores a management table (22a) in which pieces of information regarding a modulation mode, an FEC, and a frame mode of an optical signal are associated with each other, and sequentially changes the modulation mode, the FEC, and the frame mode according to the management table (22a) upon an LOS alert from a relay-side optical input/output unit (24) or an LOF alert from a DSP (25) being input thereto. Upon successfully receiving an appropriate optical signal according to the change, the monitoring control unit (22) acquires transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line in an OXC (20g), which serves as a relay apparatus, when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.Type: GrantFiled: July 12, 2019Date of Patent: November 7, 2023Assignee: Nippon Telegraph and Telephone CorporationInventors: Masatoshi Namiki, Masahiro Yokota, Hiroki Kawahara, Hiroto Takechi, Katsuhiro Araya, Masaaki Inami, Daisaku Shimazaki, Hideki Maeda
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Patent number: 11799560Abstract: An asymmetric coherent receiver includes an optical front end configured to split a received optical signal into two paths, wherein the split received optical signal experiences a different optical transfer function in one of the two paths; two photodetectors each configured to detect power one of the split received optical signals in each of the two paths to obtain corresponding electrical signals; and circuitry configured to perform electrical domain extraction of information of each of the corresponding electrical signals from the two paths, wherein the different optical transfer function provides additional information utilized in optical field reconstruction via direct detection.Type: GrantFiled: January 19, 2022Date of Patent: October 24, 2023Assignee: Ciena CorporationInventors: Xueyang Li, Maurice O'Sullivan, Zhenping Xing, David V. Plant, Mohammad E. Mousa Pasandi
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Patent number: 11709317Abstract: A wavelength demultiplexer includes a photonic circuit and a control circuit that adjusts wavelength characteristics of the photonic circuit. The photonic circuit converts two orthogonal polarized waves contained in the incident light into two same polarized waves, which are supplied to a first optical demultiplexing circuit and a second optical demultiplexing circuit provided in the photonic circuit and having the same configuration. The photonic circuit supplies a total output power of monitor lights extracted from the same positions in the first optical demultiplexing circuit and the second optical demultiplexing circuit to the control circuit. The control circuit controls a first wavelength characteristic of the first optical demultiplexing circuit and a second wavelength characteristic of the second optical demultiplexing circuit based on the total output power of the monitor lights.Type: GrantFiled: November 19, 2021Date of Patent: July 25, 2023Assignee: FUJITSU LIMITEDInventor: Akio Sugama
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Patent number: 11705969Abstract: A receiver is configured to extract a clock signal superimposed on a detection signal of light propagated to determine whether or not SNR of the detection signal is lower than SNR at which the detection signal can be demodulated; compensate a signal value of the detection signal by using a filter coefficient and output a detection signal after signal value compensation; and calculate, as the filter coefficient, a filter coefficient in which a signal value of a detection signal output from the adaptive filter is a reference value when it is determined that there is no SNR degradation, and changes the filter coefficient to a stored filter coefficient when it is determined that SNR degradation occurs.Type: GrantFiled: January 6, 2022Date of Patent: July 18, 2023Assignee: MITSUBISHI ELECTRIC CORPORATIONInventor: Keisuke Matsuda
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Patent number: 11689291Abstract: An optical full-field transmitter for an optical communications network includes a primary laser source configured to provide a narrow spectral linewidth for a primary laser signal, and a first intensity modulator in communication with a first amplitude data source. The first intensity modulator is configured to output a first amplitude-modulated optical signal from the laser signal. The transmitter further includes a first phase modulator in communication with a first phase data source and the first amplitude-modulated optical signal. The first phase modulator is configured to output a first two-stage full-field optical signal. The primary laser source has a structure based on a III-V compound semiconductor.Type: GrantFiled: June 30, 2022Date of Patent: June 27, 2023Assignee: Cable Television Laboratories, Inc.Inventors: Haipeng Zhang, Junwen Zhang, Mu Xu, Zhensheng Jia, Luis Alberto Campos
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Patent number: 11689295Abstract: A reception apparatus includes: a receiving unit configured to coherently detect an optical signal and output an electrical signal containing a modulated signal and a pilot signal; a first compensating unit configured to detect a frequency of the pilot signal by performing a DFT of the electrical signal, and determine and compensate for frequency error in the electrical signal based on a reference frequency; a frequency converting unit configured to convert the frequency of the pilot signal after the compensating such that the frequency of the pilot signal is lowered by the reference frequency; and a second compensating unit configured to determine frequency error in the modulated signal after the compensating by performing a DFT on the pilot signal after the frequency converting and detecting a frequency of the pilot signal after the frequency converting.Type: GrantFiled: February 28, 2022Date of Patent: June 27, 2023Assignees: KDDI CORPORATION, NEC Platforms, Ltd.Inventors: Shohei Beppu, Takehiro Tsuritani, Koji Igarashi, Masahiro Shigihara, Masahiro Kikuta
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Patent number: 11683093Abstract: An electric digital received signal obtained from a received optical signal is segmented into blocks of a certain length with an overlap of a length determined in advance with an adjacent block. Fourier transformation is performed for each of the blocks. The blocks subjected to the Fourier transformation are stored consecutively in time series, a coefficient determined based on a wavelength dispersion compensation amount according to one of frequency positions and a delay amount according to one of the frequency positions and one of time positions is applied to each of frequency component values included in a plurality of the stored blocks, and the blocks to which the coefficient has been applied and which are obtained by adding up the frequency component values to which the coefficient has been applied for each of the frequency positions are generated. Inverse Fourier transformation is performed on the generated blocks to which the coefficient has been applied.Type: GrantFiled: June 6, 2019Date of Patent: June 20, 2023Assignee: Nippon Telegraph and Telephone CorporationInventors: Masanori Nakamura, Seiji Okamoto, Kengo Horikoshi, Shuto Yamamoto, Takayuki Kobayashi, Yoshiaki Kisaka, Masahito Tomizawa
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Patent number: 11664905Abstract: An RF imaging receiver using photonic spatial beam processing is provided with an optical beam steerer that directs the modulated optical signals to steer the composite optical signal and move the location of the spot on the optical detector array. The optical beam steerer may be implemented with one or more phase-dependent steering units in which each unit includes a waveplate and polarization grating to steer the modulated optical signals. The optical beam steerer may be configured to act on the individual modulated optical signals to induce individual phase delays that produce a phase delay with a linear term, and possibly spherical or aspherical terms, to steer the composite optical signal in which case the optical beam steerer may be implemented, for example, with an optical phase modulator and optical antenna in each optical channel which together form an OPA, a Risley prism or a liquid crystal or MEMs spatial light modulator.Type: GrantFiled: September 2, 2021Date of Patent: May 30, 2023Assignee: Raytheon CompanyInventors: Gerald P. Uyeno, Sean D. Keller, Benn H. Gleason
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Patent number: 11662926Abstract: In a memory system an interface circuit includes an interface to a memory array, and to a data signal. The circuit includes loopback circuitry to enable loopback of received data signals without having to access the data from the memory array. The circuit can be part of a memory device, a register device, or a data buffer. The circuit interfaces to a memory array of a memory device, and performs loopback functions for a host controller that can test the operation of the interface.Type: GrantFiled: April 2, 2021Date of Patent: May 30, 2023Assignee: Intel CorporationInventors: Dean-Dexter R. Eugenio, Arvind Kumar, John R. Goles, Christopher E. Cox
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Patent number: 11646798Abstract: A receiving device includes a light source outputting local oscillation light, a detector detecting intermittent input of a burst light signal by using the local oscillation light, a first converter converting the detected burst optical signal into an electrical analog signal, an amplifier amplifying the analog signal according to a gain, a second converter converting the amplified analog signal into a digital signal, and a setting processor setting the gain of the amplifier and a wavelength of the local oscillation light instructed by a control device when setting a communication line with one of transmitting devices transmitting the burst optical signal, wherein, before setting the communication line, the setting processor switches the wavelength of the local oscillation light according to the burst optical signal transmitted from each of the transmitting devices, adjusts the gain of the amplifier and notifies the control device of the adjusted gain.Type: GrantFiled: August 25, 2021Date of Patent: May 9, 2023Assignee: FUJITSU OPTICAL COMPONENTS LIMITEDInventors: Yoshio Sakai, Toshiki Tanaka
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Patent number: 11637638Abstract: A method at a receiver comprises receiving a signal conveying symbols at respective positions within a clock cycle, the symbols comprising a data set consisting of data symbols and a pilot set consisting of pilot symbols; determining detected phases of the symbols based on the signal; generating first phase estimates based on the detected phases of a subset of the pilot set, and reference phases of the subset of the pilot set, the first phase estimates being associated with the positions of the pilot set; and generating second phase estimates based on the detected phases of the pilot set, reference phases of the pilot set, and the first phase estimates, the second phase estimates being associated with the positions of the pilot set and of at least a subset of the data set; and applying rotations to the detected phases of the symbols based on the second phase estimates.Type: GrantFiled: December 7, 2021Date of Patent: April 25, 2023Assignee: CIENA CORPORATIONInventors: James St. Leger Harley, Tung Trong Nguyen, Timothy Creasy, Blake Toplis
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Patent number: 11632180Abstract: In a coherent optical receiver device, the dynamic range considerably decreases in the case of selectively receiving the optical multiplexed signals by means of the wavelength of the local oscillator light, therefore, a coherent optical receiver device according to an exemplary aspect of the invention includes a coherent optical receiver receiving optical multiplexed signals in a lump in which signal light is multiplexed; a variable optical attenuator; a local oscillator connected to the coherent optical receiver; and a first controller controlling the variable optical attenuator by means of a first control signal based on an output signal of the coherent optical receiver; wherein the coherent optical receiver includes a 90-degree hybrid circuit, a photoelectric converter, and an impedance conversion amplifier, and selectively detects the signal light interfering with local oscillation light output by the local oscillator out of the optical multiplexed signals; and the variable optical attenuator is disposedType: GrantFiled: March 31, 2021Date of Patent: April 18, 2023Assignee: NEC CORPORATIONInventor: Kouichi Suzuki
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Patent number: 11621782Abstract: Described herein are systems and methods that perform coarse chromatic dispersion (CD) compensation by applying precomputed coarse front-end equalizer (FEE) tap weights to a receiver based on an assumed propagation distance. After a waiting period, the FEE tap weights are applied, and it is determined whether the FEE tap weights cause a decision-directed tracking of channel rotations to satisfy a stability metric. In response to the stability metric not being satisfied, the assumed propagation distance is adjusted and used to obtain updated FEE tap weights. Conversely, if the stability metric is satisfied, a fine CD compensation is performed that comprises maintaining the updated FEE tap weights; performing an iterative least-mean-squared (LMS) error adaption to adjust Back-End Equalizer (BEE) tap weights and obtain updated BEE tap weights; and using the updated BEE tap weights to adjust the FEE tap weights to, ultimately, have the BEE output an equalized data bit stream.Type: GrantFiled: April 26, 2022Date of Patent: April 4, 2023Assignee: Maxim Integrated Products, Inc.Inventor: Charles Razzell
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Patent number: 11611395Abstract: First compensation circuitry includes a first digital filter compensating a phase difference between a phase of a symbol of a received signal and a sampling timing, and first filter coefficient calculation circuitry calculating a filter coefficient of the first digital filter as a first filter coefficient. Second filter coefficient calculation circuitry calculates, as a second filter coefficient, a filter coefficient for adaptive equalization that compensates distortion due to temporally changing polarization dispersion, based on an output of the first digital filter. Coefficient combination circuitry combines the first filter coefficient and the second filter coefficient. Second compensation circuitry includes a second digital filter which uses a filter coefficient combined by the coefficient combination circuitry and performs a compensation of the phase difference between the phase of the symbol of the received signal and the sampling timing, and a process of the adaptive equalization at the same time.Type: GrantFiled: October 7, 2019Date of Patent: March 21, 2023Assignee: NTT ELECTRONICS CORPORATIONInventors: Tomohiro Takamuku, Mitsuteru Yoshida, Tsutomu Takeya, Kazuhito Takei, Katsuichi Oyama, Tomoharu Semboku
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Patent number: 11601204Abstract: A method is provided for assessing the quality of an optical transmitter and/or its interoperability with a receiver. The method includes obtaining an optical signal output by an optical transmitter and performing coherent optical-to-electrical detection of the optical signal to produce an in-phase receive signal and a quadrature receive signal. The method further includes a computing device emulating a worst-case configuration of an optical fiber with which the optical transmitter is to be used, based on the in-phase receive signal and the quadrature receive signal to produce a noise contribution associated with the worst-case characteristics of the optical fiber and determining a figure of merit of the optical transmitter based on the noise contribution.Type: GrantFiled: July 16, 2021Date of Patent: March 7, 2023Assignee: CISCO TECHNOLOGY, INC.Inventors: Fabio Bottoni, Alessandro Cavaciuti
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Patent number: 11581951Abstract: Apparatuses and methods for far-end monitoring of transmitter IQ skew in a DSCM system are described. Soft symbols for a given subchannel and a corresponding mirror subchannel are used as joint inputs to a MIMO equalizer. The hard decision symbols for the given subchannel and mirror subchannel are used as references to compute the equalizer coefficients. An estimated phase or estimated transmitter IQ skew is computed for at least the given subchannel using the equalizer coefficients. The computation is repeated to obtain estimated phase or estimated transmitter skew for all subchannels. The transmitter IQ skew is computed using the estimates from all subchannels. The computation is performed for each polarization. The computed transmitter IQ skew is communicated back to the transmitter via optical path (for correcting the skew).Type: GrantFiled: January 31, 2022Date of Patent: February 14, 2023Assignee: HUAWEI TECHNOLOGIES CO., LTD.Inventors: Wing Chau Ng, Xuefeng Tang, Chuandong Li