Abstract: A dual wavelength Optical Time Domain Reflectometer (OTDR) system, embedded in a network element, includes a first OTDR source for wavelength ?1; a second OTDR source for wavelength ?2; an OTDR measurement subsystem adapted to measure backscatter signals ?1_BACK, ?2_BACK associated with the wavelength ?1 and the wavelength ?2; and one or more ports connecting the first OTDR source, the second OTDR source, and the OTDR measurement subsystem to one or more fiber pairs; wherein wavelength ?1 and wavelength ?2 are each outside of one or more signal bands with traffic-bearing channels, thereby enabling operation in-service with the traffic-bearing channels.

Abstract: A polarimeter system integrated into an optical line system includes a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light from the filter and to measure various outputs of the varied arrangement to derive measurement of State of Polarization (SOP) of the input light.

Abstract: A method for noise suppression in a colorless optical add/drop system implemented prior to a colorless optical add/drop device includes, subsequent to receiving an optical signal from an optical modem, filtering the optical signal with a wavelength blocking filter to suppress out of band Amplified Stimulated Emission (ASE) in order to prevent noise funneling in the colorless optical add/drop device; and providing the filtered optical signal with the out of band ASE suppressed therein to a multiplexer port in the colorless optical add/drop device. The method can include, prior to the filtering, amplifying the optical signal with a single channel amplifier, wherein the single channel amplifier can include a pump laser shared with one or more additional single channel amplifiers.

Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: A dual wavelength Optical Time Domain Reflectometer (OTDR) system, embedded in a network element, includes a first OTDR source for wavelength ?1; a second OTDR source for wavelength ?2; an OTDR measurement subsystem adapted to measure backscatter signals ?1_BACK, ?2_BACK associated with the wavelength ?1 and the wavelength ?2; and one or more ports connecting the first OTDR source, the second OTDR source, and the OTDR measurement subsystem to one or more fiber pairs; wherein wavelength ?1 and wavelength ?2 are each outside of one or more signal bands with traffic-bearing channels, thereby enabling operation in-service with the traffic-bearing channels.

Abstract: A method of validating connections in an optical add/drop multiplexer (OADM) that includes a plurality of modules configured to route optical signals through the OADM, and at least one multi-fiber cable connecting modules of the OADM. A light source coupled to a first port of a first module is controlled to emit a test light. A determination is made whether or not the test light is received at a first photo-detector connected to a second port. Continuity of a connection between the first port and the second port is validated when the test light is received at the first photo-detector.

Abstract: A method of analysing performance of an optical fiber link. As a preliminary step, a reference trace indicative of a distributed optical performance of the optical fiber link is derived. During in-service operation of the optical fiber link, an Optical Time Domain Reflectometry (OTDR) sub-system measures an OTDR trace with Raman amplification ON, and a real-time cumulative Raman Gain profile of the optical fiber link is calculated based on the reference trace and the measured OTDR trace.

Abstract: A method of validating connections in an optical add/drop multiplexer (OADM) that includes a plurality of modules configured to route optical signals through the OADM, and at least one multi-fiber cable connecting modules of the OADM. A light source coupled to a first port of a first module is controlled to emit a test light. A determination is made whether or not the test light is received at a first photo-detector connected to a second port. Continuity of a connection between the first port and the second port is validated when the test light is received at the first photo-detector.

Abstract: A method of analysing performance of an optical fiber link. As a preliminary step, a reference trace indicative of a distributed optical performance of the optical fiber link is derived. During in-service operation of the optical fiber link, an Optical Time Domain Reflectometry (OTDR) sub-system measures an OTDR trace with Raman amplification ON, and a real-time cumulative Raman Gain profile of the optical fiber link is calculated based on the reference trace and the measured OTDR trace.

Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: Systems and methods are described for reducing coherence effect in narrow line-width light sources through various modulation techniques. The systems and methods can include a narrow line-width laser source with a thermoelectric cooler thermally coupled thereto and a controller communicatively coupled to the thermoelectric cooler. The controller is configured to provide a varied input signal to the thermoelectric cooler to reduce coherence of the narrow line-width laser source by artificially broadening the narrow line-width on a time averaged basis. The systems and methods can also include direct modulation of the narrow line-width laser source. The systems and methods can include a narrow line-width Optical Time Domain Reflectometer (OTDR). The systems and methods can also include direct modulation of the narrow line-width laser source with or without the varied input signal to the thermoelectric cooler.

Abstract: The embedded apparatus disclosed herein may measure reflection coefficient values associated with back reflections in a fiber optics transmission system during a variable detection window to detect normal conditions, simulated Brillouin scattering (SBS), or excessive back reflections triggering remedial action. For example, the back reflections may indicate normal conditions if the reflection coefficients measured during an entire detection window remained below a threshold or a maximum reflection coefficient observed therein was below the threshold. Alternatively, the back reflections may trigger remedial action if the reflection coefficients measured in the entire detection window exceeded the threshold or a minimum reflection coefficient observed therein was above the threshold.

Abstract: A method, optical module, and optical amplifier are configured to detect fiber discontinuities at or near a port from which high powered optical signals are input into a fiber span. These fiber discontinuities can include fiber pinches, and are detected by monitoring for slight changes in a backscatter signal. Detection is quick and efficient based on the backscatter signal being attenuated by the fiber discontinuities twice, namely once as the high powered optical signals and again as the associated backscatter signal of the high powered optical signals returning to the port. Various remedial actions can be taken upon detecting fiber pinches at or near the port.

Abstract: The present disclosure provides reconfigurable optical add drop multiplexer (ROADM) node automatic topology discovery systems and methods providing a mapping of optical connections within a mesh optical network that includes tunable lasers and multi-degree ROADM's with colorless/directionless add/drop. The present disclosure may include additional transceiver, receiver, and add/drop filter equipment integrated in or disposed at a ROADM degree. This equipment supports a so-called topology wavelength which is one of a plurality of wavelengths supported by a wavelength division multiplexed (WDM) system that is dedicated and used solely for topology discovery. The topology wavelength may be utilized by the system to detect interconnects between ROADM degrees and between XCVRs/CDMDs. Further, the automated topology discovery may be integrated within a management system and/or control plane.

Abstract: Raman amplifier systems and methods with an integrated Optical Time Domain Reflectometer (OTDR) for integrated testing functionality include an amplifier system, an OTDR and telemetry subsystem, and a method of operation. The OTDR and telemetry subsystem is configured to operate in an OTDR mode when coupled to a line in port and to operate in a telemetry mode when coupled to a line out port. The OTDR and telemetry subsystem enables on-demand fiber testing while also operating as a telemetry channel that is both a redundant optical service channel (OSC) and provides a mechanism to monitor Raman gain over time. The OTDR and telemetry subsystem minimizes cost and space by sharing major optical and electrical components between the integrated OTDR and other functions on the Raman amplifier.

Abstract: A method, optical module, and optical amplifier are configured to detect fiber discontinuities at or near a port from which high powered optical signals are input into a fiber span. These fiber discontinuities can include fiber pinches, and are detected by monitoring for slight changes in a backscatter signal. Detection is quick and efficient based on the backscatter signal being attenuated by the fiber discontinuities twice, namely once as the high powered optical signals and again as the associated backscatter signal of the high powered optical signals returning to the port. Various remedial actions can be taken upon detecting fiber pinches at or near the port.

Abstract: Systems and methods are described for reducing coherence effect in narrow line-width light sources through various modulation techniques. The systems and methods can include a narrow line-width laser source with a thermoelectric cooler thermally coupled thereto and a controller communicatively coupled to the thermoelectric cooler. The controller is configured to provide a varied input signal to the thermoelectric cooler to reduce coherence of the narrow line-width laser source by artificially broadening the narrow line-width on a time averaged basis. The systems and methods can also include direct modulation of the narrow line-width laser source. The systems and methods can include a narrow line-width Optical Time Domain Reflectometer (OTDR). The systems and methods can also include direct modulation of the narrow line-width laser source with or without the varied input signal to the thermoelectric cooler.

Abstract: The present invention provides a directionless reconfigurable optical add/drop multiplexer (ROADM) system. The present invention provides a scalable all-optical switching element that includes a combination of 1×N wavelength selective switches (WSS), 1×N splitters/combiners, optical amplifiers, and tunable filters to provide a fully non-blocking solution which can be deployed in a scalable manner. The 1×N splitters are configured to split multiples copies of a plurality of drop wavelengths which can be amplified and sent to a tunable filter which selects out a particular wavelength for drop. The 1×N combiners are configured to combine multiple add wavelengths for egress transmission.

Abstract: Systems and methods for extended reach low differential latency optical networking with optical amplifiers and dispersion compensation modules configured to minimize latency between transmit and receive paths are provided. Additionally, systems and methods are provided for incorporating absolute time references wherein the relative accuracy of clock time between various servers used in various multi-site enterprises is required. The transport systems and methods are used in conjunction with low differential latency systems. The transport systems and methods provide that the differential latency between transmit and receive directions is maintained within about +/?5 microseconds of the transmit/receive path differential delay requirement in order to perform within the overall parameters of the low differential latency system architecture.