Abstract: We disclose embodiments of a WDM transmitter having an in-band OTDR capability for at least a subset of the WDM channels thereof. In an example embodiment, an OTDR-enabled WDM channel of the WDM transmitter is implemented using an optical transceiver that comprises an optical transmitter and a coherent optical receiver. The optical transmitter is configured to generate a modulated optical signal by modulating a respective carrier wavelength, transmit the modulated optical signal through an optical link as a component of the corresponding WDM signal, and provide the respective carrier wavelength to the coherent optical receiver for being used therein as an optical local oscillator. The optical receiver is configured to estimate an impulse response of the optical link by coherently detecting and processing a return optical signal produced within the optical link due to distributed reflection and/or backscattering of the modulated optical signal.

Abstract: We disclose embodiments of a WDM transmitter having an in-band OTDR capability for at least a subset of the WDM channels thereof. In an example embodiment, an OTDR-enabled WDM channel of the WDM transmitter is implemented using an optical transceiver that comprises an optical transmitter and a coherent optical receiver. The optical transmitter is configured to generate a modulated optical signal by modulating a respective carrier wavelength, transmit the modulated optical signal through an optical link as a component of the corresponding WDM signal, and provide the respective carrier wavelength to the coherent optical receiver for being used therein as an optical local oscillator. The optical receiver is configured to estimate an impulse response of the optical link by coherently detecting and processing a return optical signal produced within the optical link due to distributed reflection and/or backscattering of the modulated optical signal.

Abstract: Systems and methods for calculating a relative temperature of a fiber-optic cable using bi-directional analysis traces with an optical time-domain reflectometer (“OTDR”). Analysis of bi-directional traces along a length of fiber-optic cable yields a scaled local backscatter coefficient of the fiber. Accordingly, an initial set of measurement data is collected at a first time interval and a base scaled local backscatter along a fiber is calculated. A subsequent set of measurement data is collected at a second time interval and a subsequent scaled local backscatter along the fiber is calculated. The exemplary systems and methods described herein determines a change in scaled local backscatter as a function of a difference between the base scaled local backscatter and at least the subsequent scaled local scaled local backscatter along the fiber, and then determines a relative temperature variation of the fiber as a function of the change in scaled local backscatter.

Abstract: Described herein are systems and methods for uniquely identifying, or “fingerprinting,” optical fibers based upon hi-resolution measurements of the backscattered light. One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to retrieve a profile for an intended fiber, the profile including unique measurement data of the intended fiber, receive from an optical frequency-domain reflectometer further measurement data from a connected fiber within a network, compare the unique measurement data of the intended fiber to the further measurement data of the connected fiber, and confirm an identity of the connected fiber as being the intended fiber when the unique measurement data matches the further measurement data, and trigger an alert when the unique measurement data does not match the further measurement data.

Abstract: Described herein are systems and methods for uniquely identifying, or “fingerprinting,” optical fibers based upon measurements from an optical time-domain reflectometer (“OTDR”). One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to retrieve a profile for an intended fiber, the profile including unique measurement data of the intended fiber, collect further measurement data from a connected fiber within a network, compare the unique measurement data of the intended fiber to the further measurement data of the connected fiber, and confirm an identity of the connected fiber as being the intended fiber when the unique measurement data matches the further measurement data, and trigger an alert when the unique measurement data does not match the further measurement data.

Abstract: Described herein are systems and methods for calculating a relative temperature of a fiber-optic cable using bi-directional analysis traces with an optical time-domain reflectometer (“OTDR”). Analysis of bi-directional traces along a length of fiber-optic cable yields a scaled local backscatter coefficient of the fiber. Accordingly, an initial set of measurement data is collected at a first time interval and a base scaled local backscatter along a fiber is calculated. A subsequent set of measurement data is collected at a second time interval and a subsequent scaled local backscatter along the fiber is calculated. The exemplary systems and methods described herein determines a change in scaled local backscatter as a function of a difference between the base scaled local backscatter and at least the subsequent scaled local scaled local backscatter along the fiber, and then determines a relative temperature variation of the fiber as a function of the change in scaled local backscatter.

Abstract: Described herein are systems and methods for enhancing sensitivity of an optical time-domain reflectometer (“OTDR”) using bi-directional analysis techniques. One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to collect a first set of measurement data at a first resolution to provide a relative backscatter of the fiber, collect a second set of measurement data taken at a second resolution to calculate loss along the length of fiber, and combine the first set of measurement data with the second set of measurement data to calculate the loss along the fiber at the first resolution.

Abstract: Described herein are systems and methods for enhancing the resolution of an optical time-domain reflectometer (“OTDR”). One embodiment of the disclosure of this application is related to a device, comprising an optical measuring component collecting a first set of measurement data from a forward trace along an optical fiber with the optical measuring device using depolarized light, and a processing component calculating loss along the length of fiber. The optical measuring device further collects a second set of measurement data from a backward trace along the optical fiber with the optical measuring device using depolarized light.

Abstract: Described herein are systems and methods for calculating a relative temperature of a fiber-optic cable using bi-directional analysis traces with an optical time-domain reflectometer (“OTDR”). Analysis of bi-directional traces along a length of fiber-optic cable yields a scaled local backscatter coefficient of the fiber. Accordingly, an initial set of measurement data is collected at a first time interval and a base scaled local backscatter along a fiber is calculated. A subsequent set of measurement data is collected at a second time interval and a subsequent scaled local backscatter along the fiber is calculated. The exemplary systems and methods described herein determines a change in scaled local backscatter as a function of a difference between the base scaled local backscatter and at least the subsequent scaled local scaled local backscatter along the fiber, and then determines a relative temperature variation of the fiber as a function of the change in scaled local backscatter.

Abstract: Methods and systems for PMD compensation in an optical communication system are implemented by transmitting multiple optical signals through a common optical conduit to an optical compensator that adjustably rotates the polarization states of the multiple optical signals and transmits the rotated optical signals to an optical receiver. The receiver, upon sensing an excessive error condition, commands the optical compensator to change the polarization state of rotation, which changes the PMD profile of the received optical signals.

Abstract: Described herein are systems and methods for enhancing sensitivity of an optical time-domain reflectometer (“OTDR”) using bi-directional analysis techniques. One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to collect a first set of measurement data at a first resolution to provide a relative backscatter of the fiber, collect a second set of measurement data taken at a second resolution to calculate loss along the length of fiber, and combine the first set of measurement data with the second set of measurement data to calculate the loss along the fiber at the first resolution.

Abstract: Described herein are systems and methods for uniquely identifying, or “fingerprinting,” optical fibers based upon measurements from an optical time-domain reflectometer (“OTDR”). One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to retrieve a profile for an intended fiber, the profile including unique measurement data of the intended fiber, collect further measurement data from a connected fiber within a network, compare the unique measurement data of the intended fiber to the further measurement data of the connected fiber, and confirm an identity of the connected fiber as being the intended fiber when the unique measurement data matches the further measurement data, and trigger an alert when the unique measurement data does not match the further measurement data.

Abstract: Described herein are systems and methods for enhancing the resolution of an optical time-domain reflectometer (“OTDR”). One embodiment of the disclosure of this application is related to a device, comprising an optical measuring component collecting a first set of measurement data from a forward trace along an optical fiber with the optical measuring device using depolarized light, and a processing component calculating loss along the length of fiber. The optical measuring device further collects a second set of measurement data from a backward trace along the optical fiber with the optical measuring device using depolarized light.

Abstract: Described herein are systems and methods for uniquely identifying, or “fingerprinting,” optical fibers based upon hi-resolution measurements of the backscattered light, such as can be performed by an optical frequency-domain reflectometer (“OFDR”). One embodiment of the disclosure of this application is related to a computer readable storage medium including a set of instructions that are executable by a processor. The set of instructions being operable to retrieve a profile for an intended fiber, the profile including unique measurement data of the intended fiber, receive from the OFDR further measurement data from a connected fiber within a network, compare the unique measurement data of the intended fiber to the further measurement data of the connected fiber, and confirm an identity of the connected fiber as being the intended fiber when the unique measurement data matches the further measurement data, and trigger an alert when the unique measurement data does not match the further measurement data.

Abstract: A method and apparatus is provided for obtaining status information from a given location along an optical transmission path. The method begins by generating a cw probe signal having a prescribed frequency that is swept over a prescribed frequency range. The cw probe signal is transmitted over the optical path and a returned COTDR signal in which status information concerning the optical path is embodied is received over the optical path. A receiving frequency within the prescribed frequency range of the returned COTDR signal is detected to obtain the status information. The detecting step includes the step of sweeping the receiving frequency at a rate equal to that of the prescribed frequency. A period associated with the receiving frequency is temporally offset from a period associated with the prescribed frequency.

Abstract: Methods and systems for higher-order PMD compensation are implemented by developing an effective mathematical model and applying economical design techniques to the model. By assuming a constant precession rate for a narrow band of frequencies in an optical signal, a simplified model of a higher-order PMD compensator can be derived. The model can be used produce an economical compensator by making multiple uses of selected optical components.

Abstract: Methods and systems for PMD compensation in an optical communication system are implemented by transmitting multiple optical signals through a common optical conduit to an optical compensator that adjustably rotates the polarization states of the multiple optical signals and transmits the rotated optical signals to an optical receiver. The receiver, upon sensing an excessive error condition, commands the optical compensator to change the polarization state of rotation, which changes the PMD profile of the received optical signals.

Abstract: A method is provided for locating a fault in one or more optical amplifiers operating in saturation and located along an optical transmission path. The method begins by generating a coherent optical time domain reflectometry (COTDR) trace representing a backscattered and/or reflected optical power level along the transmission path and comparing the trace to a reference trace to generate a difference trace that represents a change in gain. The change in gain is assigned to at least one of the optical amplifiers based on the difference trace. The method comprises assigning the difference trace to faults in the optical amplifiers, equating the difference trace with a linear combination of difference trace vectors each arising from a fault in a different one of the optical amplifiers, and iterating to determine a coefficient value associated with each difference trace vector. Each nonzero coefficient value denotes a fault in an optical amplifier.

Abstract: Methods and systems for PMD compensation in an optical communication system are implemented by transmitting multiple optical signals through a common optical conduit to an optical compensator that adjustably rotates the polarization states of the multiple optical signals and transmits the rotated optical signals to an optical receiver. The receiver, upon sensing an excessive error condition, commands the optical compensator to change the polarization state of rotation, which changes the PMD profile of the received optical signals.

Abstract: A method for entering a market with high barriers to entry and a plurality of proprietary business elements includes converting at least one of the business elements into a universal business element that can accept a wide variety of inputs from other business elements, while converting a remaining one of the plurality of business elements to commoditized business elements. In addition, a market of a resulting business is limited so that the resulting business straddles a gap between two subdivisions of the market. Thus, a combination of technology and market division enables conversion of otherwise proprietary system to commodity equipment that can work with a wide variety of existing vendor equipment while competing technologically with highly engineered solutions.