Ciena Corporation

Jun Bao

Balakrishnan Sridhar

Jean-Luc Archambault

Michael Y Frankel

Vipul Bhatnagar

Harshad P Sardesai

Shan Zhong

Si Hyung Cho

Charles Haggans

Mahir A Nayfeh

Zhonghua Zhu

Hua Jiao

Andrei Csipkes

Michael George Taylor

Donald J Miller

Waqar Mahmood

Scott Kohlert

James E DeGrange, Jr

Michael H Shahine

Clark Scrandis

Xiaohui Yang

John H Brownlee

Alan D Stummer

Jon Tsou

Joseph F Ferment, Iii

An optical module includes an optical amplifier configured to amplify Wavelength Division Multiplexing (WDM) channels transmitted on a fiber; and an optical time domain reflectometer (OTDR) configured to transmit an OTDR signal on the fiber and detect a back-scattered signal based thereon to test the fiber, wherein a wavelength of the OTDR signal is one of i) between one or more wavelengths associated with the optical amplifier and one or more wavelengths associated with the WDM channels and ii) greater than the one or more wavelengths associated with the WDM channels, for in-service operation of the OTDR.

Raman amplifier system and method with integrated optical time domain reflectometer

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. Otherwise, the back reflections may indicate the SBS effect if the reflection coefficients measured during the detection window included points above and below the threshold or the minimum and maximum reflection coefficients observed therein were below and above the threshold.

Embedded apparatus to monitor simulated brillouin scattering from Raman amplifier in fiber optics transmission system

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.

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.

Method and system for optical connection validation in a reconfigurable optical add-drop multiplexer (ROADM) node

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.

Systems and methods reducing coherence effect in narrow line-width light sources

Raman amplifier gain compression systems and methods based on signal power monitoring are described which estimate distributed Raman amplifier saturation based on a total power measurement at an output of a distributed Raman amplifier and correct for any changes by adjusting the pump power. Since the power measurement, gain estimation, and the pump control and done locally at the Raman amplifier, the duration of any transients is minimized. The systems and methods quickly detect transients on a fiber link using a power monitor in the Raman amplifier, estimate the change in gain due to change in input power from distributed Raman gain, and perform a feedback loop that corrects pump power to eliminate the change in Raman gain locally.

Raman amplifier gain compression systems and methods based on signal power monitoring

An extended dynamic range optical amplifier, a method of operation, and a line amplifier configuration include an optical amplifier that can be optimized for high or low span loss conditions by switching an internal stage in or out of an internal light path within the amplifier. The extended dynamic range optical amplifier can include a low gain mode and a high gain mode with an internal switch to switch out a gain mid-stage in a low gain mode to extend the useful dynamic range of the amplifier. Further, the extended dynamic range optical amplifier can use residual pump power from an initial stage to pump the gain mid-stage in the high gain mode. Additionally, the extended dynamic range optical amplifier includes remapping of gain in the initial stage and the gain mid-stage to optimize the amplifier noise performance based on the maximum output power of the amplifier.

Extended dynamic range optical amplifier

Optical service channel (OSC) systems and methods over high loss links are described utilizing redundant telemetry channels. A first telemetry channel provides a low bandwidth communication channel used when Raman amplification is unavailable on a high loss link for supporting a subset of operations, administration, maintenance, and provisioning (OAM&P) communication. A second telemetry channel provides a high bandwidth communication channel for when Raman amplification is available to support full OAM&P communication. The first and second telemetry operate cooperatively ensuring nodal OAM&P communication over high loss links (e.g., 50 dB) regardless of operational status of Raman amplification.

Optical service channel systems and methods over high loss links

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.

High-powered optical module safety systems and methods

The present disclosure provides optimized configurations for a directionless reconfigurable optical add/drop multiplexer application. The present invention includes an add module with improved optical signal-to-noise through placing amplifiers prior to a multi-cast optical switch. The present invention includes various drop module configurations utilizing distributed gain, channel selective filters, and bi-directional configurations to reduce power consumption and complexity. Additionally, the present invention includes an integrated broadcast and select architecture.

Optimized directionless optical add/drop module systems and methods

The present disclosure provides high-degree reconfigurable optical add-drop multiplexing (ROADM) systems using bi-directional wavelength selective switches (WSSs) and optical circulators. A single WSS is utilized on each degree of a node in a bi-directional manner, i.e. both ingress and egress share the same WSS. Advantageously, the present invention eliminates conventional splitters/combiners thereby capping intra-node insertion loss to a certain value regardless of the number of degrees. More importantly, the present invention reduces noise penalty associated with high-degree nodes while minimizing cost.

High-degree reconfigurable optical add-drop multiplexing systems using bi-directional wavelength selective switches

The present disclosure relates to streamlining optical module and/or subassembly development, manufacturing, and testing through introducing a memory component within a module and/or subassembly that is utilized with a host module for system calibration and/or configuration. In an exemplary embodiment, the present invention can streamline optical amplifier (EDFA) module and/or subassembly development, manufacturing, and testing. The present invention includes an optical module/sub-assembly without control circuitry, i.e. a 'dumb module', but with a memory that is used to load relevant data from a supplier. This data is utilized to calibrate, test, and configure the optical module/sub-assembly in a host module. The host module includes control circuitry to access this memory in the optical module/sub-assembly and to calibrate, test, configure, and control the optical module/sub-assembly. Advantageously, this additional memory reduces manufacturing time without the disadvantage of adding complexity in the optical module/sub-assembly.

Optical module manufacturing and testing systems and methods

The present invention provides a signal distribution module for use in a directionless reconfigurable optical add/drop multiplexer application, including: a multi-cast switch having a plurality of input ports and a plurality of output ports; a plurality of optical amplifiers coupled to the plurality of input ports of the multi-cast switch, wherein the plurality of optical amplifiers form an optical amplifier array; a tunable optical splitter coupled to the plurality of optical amplifiers; and a pump laser coupled to the tunable optical splitter.

Signal distribution module for a directionless reconfigurable optical add/drop multiplexer

Optical amplifying method and apparatus are proposed. Constant gain amplifiers operate such that the output power of the amplifier generally tracks the input power. However, optical systems are not perfect and the input to the optical amplifier stage includes not only the desired signal, but also includes accumulated effects of the imperfections. The imperfections include losses of the fiber sections, variations in laser powers, and drifts. Thus, simple amplification not only amplifies the desired signal, but also amplifies accumulated imperfections. Such imperfections occur over time and are generally small in magnitude. By operating the amplifier such that amplification of small variations is suppressed while allowing for tracking of large input variations, amplifying the accumulated imperfections is minimized.

Growing community of inventors

Ellicott City, MD, United States of America

Jun Bao