Abstract: This patent document discloses techniques and devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques. The optical sensors for sensing the current or temperature can be configured as a polarization-insensitive optical sensor in either an optical transmissive configuration or an optical reflective configuration.

Abstract: This patent application discloses techniques and devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques. An optical current sensor head is located near or at a current-carrying conductor so that a magnetic field associated with the current is present at a Faraday material and the optical detection unit detects the light from the Faraday material to determine a magnitude of the current. An optical temperature sensor head is located near or at a location so that the temperature at a temperature-sensing Faraday material is reflected by the optical polarization rotation which is detected to determine the temperature.

Abstract: The disclosed technology includes, among others, methods and devices for measuring distributed fiber bend or stress related characteristics along an optical path of fiber under test (FUT) uses both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: Techniques and devices for measuring polarization crosstalk in polarization maintaining fiber by placing the PM fiber in a 1-dimensional or 2-dimensional configuration for sensing stress or strain exerted on the PM fiber at different locations along the fiber with a high spatial sensing resolution.

Abstract: The present invention provides a system and method for TCP High Availability. The system concurrently delivers incoming data streams to AMB and SMB, concurrently sends outgoing data streams originated from AMB to SMB and peer routers, synchronizes the incoming and outgoing data streams between AMB and SMB, and accelerates the synchronizations of the incoming and outgoing data streams between AMB and SMB.

Abstract: The disclosed technology in this patent document includes, among others, methods apparatus for distributed measuring at least one fiber bend or stress related characteristics along an optical path of fiber under test (FUT) uses both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: Imaging devices and processing techniques based on imaging information along the depth direction in an optical coherent tomography (OCT) image are disclosed to enhance observed morphological features. The methods and systems obtain different OCT images of the target object under different reference path lengths, process the different OCT images to obtain a derivative with respect to the signal path length of image information of the different images, and processing the derivative to extract improved image information of the target object. The derivatives may be in a form related to a gradient value of the normalized OCT image intensity, or an attenuation coefficient.

Abstract: Optical gyroscope devices and methods based on optical interferometric configurations to minimize optical loss and enhance the device energy efficiency. In one implementation, optical polarization control is provided in an optical gyroscope to reduce the optical loss in routing light to and from an optical ring that senses the rotation.

Abstract: Techniques and devices for measuring stress, strain, or temperature based on polarization crosstalk analysis in birefringence optical birefringent media including polarization maintaining fiber. The disclosed techniques and devices can be implemented to measure polarization crosstalk distribution in polarization maintaining fiber by placing the PM fiber in a 1-dimensional or 2-dimensional configuration for sensing temperature, stress or strain in the PM fiber at different locations along the fiber with a high spatial sensing resolution. In some implementations, the disclosed techniques and devices can be implemented to simultaneously measure stress, strain and temperature from analyzing the probe light. For example, both temperature and stress/strain can be simultaneously measured by using the same sensors to extract and separate temperature measurements from stress/strain measurements.

Abstract: Techniques and devices for measuring stress, strain, or temperature based on polarization crosstalk analysis in birefringence optical birefringent media including polarization maintaining fiber. The disclosed techniques and devices can be implemented to measure polarization crosstalk distribution in polarization maintaining fiber by placing the PM fiber in a 1-dimensional or 2-dimensional configuration for sensing temperature, stress or strain in the PM fiber at different locations along the fiber with a high spatial sensing resolution. In some implementations, the disclosed techniques and devices can be implemented to simultaneously measure stress, strain and temperature from analyzing the probe light. For example, both temperature and stress/strain can be simultaneously measured by using the same sensors to extract and separate temperature measurements from stress/strain measurements.

Abstract: Optical gyroscope devices and methods based on optical interferometric configurations to minimize optical loss and enhance the device energy efficiency. In one implementation, optical polarization control is provided in an optical gyroscope to reduce the optical loss in routing light to and from an optical ring that senses the rotation.

Abstract: The disclosed technology includes, among others, methods and devices for measuring distributed fiber bend or stress related characteristics along an optical path of fiber under test (FUT) uses both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: Techniques and devices for measuring polarization crosstalk in polarization maintaining fiber by placing the PM fiber in a 1-dimensional or 2-dimensional configuration for sensing stress or strain exerted on the PM fiber at different locations along the fiber with a high spatial sensing resolution

Abstract: This patent document relates to optical devices and optical sensing techniques including optical gyroscopes and optically sensing rotation. Sensing of rotation can be used in a wide range of applications, including, e.g., navigation, motion sensing, motion control including object stability control, game console controllers, hand-held devices such as smartphones. Optical gyroscopes can be designed to use rotation-induced changes in the optical interference pattern of two counter-propagating optical beams to measure the rotation. Many optical gyroscopes are based on an optical Sagnac interferometer configuration including various interferometric fiber-optic gyroscopes (IFOGs). Such optical gyroscopes can be designed without moving parts and thus eliminate the wear and tear in other gyroscopes with an oscillating proof mass or a moving component.

Abstract: Techniques and devices for measuring polarization crosstalk in birefringence optical media including polarization maintaining fiber.

Abstract: This patent application discloses techniques and devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques. An optical current sensor head is located near or at a current-carrying conductor so that a magnetic field associated with the current is present at a Faraday material and the optical detection unit detects the light from the Faraday material to determine a magnitude of the current. An optical temperature sensor head is located near or at a location so that the temperature at a temperature-sensing Faraday material is reflected by the optical polarization rotation which is detected to determine the temperature.

Abstract: The disclosed technology in this patent document includes, among others, methods apparatus for distributed measuring at least one fiber bend or stress related characteristics along an optical path of fiber under test (FUT) uses both a light input unit and a light output unit connected to the FUT at one single end.

Abstract: Imaging devices and processing techniques based on imaging information along the depth direction in an optical coherent tomography (OCT) image are disclosed to enhance observed morphological features. The methods and systems obtain different OCT images of the target object under different reference path lengths, process the different OCT images to obtain a derivative with respect to the signal path length of image information of the different images, and processing the derivative to extract improved image information of the target object. The derivatives may be in a form related to a gradient value of the normalized OCT image intensity, or an attenuation coefficient.

Abstract: A communications network comprising components configured to implement a method comprising analyzing a path between a first end point and a second end point, and identifying a partial fault along the path is disclosed. Also disclosed is a method for communicating information within a network, the method comprising: defining a path traversing a plurality of nodes, receiving a fault report from an intermediate node, determining whether the fault report affects the path, and responsive to the determination that the fault report affects the path, transmitting the fault report to an upstream or downstream node in the path.

Abstract: Techniques, devices and applications are provided for monitoring a polarization mode dispersion (PMD) effect in an optical signal.