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Verizon, EXFO, and General Photonics Mark First PMD Measurement

Exhibitor News


GENERAL PHOTONICS: Rafael Larin 1.818.541.9595 Tao Yu 1.909.590.5473 ext. 109 VERIZON: Lynn Staggs 1.918.590.2403 EXFO: Maryse Brodeur 1.418.683.0913 ext. 3429

Verizon, EXFO, and General Photonics Mark First PMD Measurement

Joint Field Trial Demonstrates Polarization Mode Dispersion Can Be Accurately Measured on Live System Without Impact to Traffic-bearing Channels

Los Angeles (OFC / NFOEC), Calif. – March 9, 2011 – Verizon, EXFO, and General Photonics have successfully measured polarization mode dispersion (PMD) on a traffic-bearing long haul network without impacting neighboring channels carrying live traffic. PMD is measured to determine system impairments for 40G and 100G signal transmissions. In field trials performed on the Verizon network, two novel methods were used to measure PMD. One method used General Photonics’ PMDPro PMD-1000 and SmartLight TCA-1000 solutions and was based on light-path PMD compensation. The other method used EXFO prototype equipment that employed algorithms in the company’s FTB-5700 Dispersion Analyzer and was based on statistical analysis of randomly polarized test signals. Both methods were performed on idle channels of a traffic-bearing long-haul network. When compared with the expected PMD value of the route, measurements showed a high level of accuracy with no adverse impact on the working channels, demonstrating both methods are suitable for measuring PMD on traffic-bearing systems.

Details of the field trial will be provided during OFC/NFOEC 2011 at the Los Angeles Convention Center, March 9, 2011 at 2:00 PM in session NWC4, by Dr. T.J. Xia, Distinguished Member of Technical Staff at Verizon.

"Advancing technology in PMD measurement -- a key component of fiber quality -- is an important step toward improving network performance," said Glenn Wellbrock, director of optical transport network architecture for Verizon. “Successfully proving we can measure PMD of an end-to-end light path in a meshed network such as Verizon’s, with no impact on the performance of live channels is a significant advancement in measurement technology.”

Previously, traditional PMD measurement has only been performed on dark fiber spans without any equipment and no way to collect PMD information after the fiber is put into service. In contrast, these two new PMD measurement methods can be used to accurately measure the PMD of a traffic-carrying fiber route with active and passive components and mixed fiber sections, including EDFAs, multiplexers, demultiplexers, ROADMs, and optical fibers.

"The light-path PMD compensation method is simple, fast and only requires an optical source with a bandwidth contained in a DWDM channel of 50GHz spacing," said Steve Yao, founder and CEO of General Photonics. "There is absolutely no impact to the live long-haul and ultra-long-haul traffic of the service provider. Only a few seconds are required to make a measurement. Either a channelized ASE source with a bandwidth around 0.2 nm or a 40G signal of any modulation format can be used as the signal source for the PMD monitoring."

Said Gregory W. Schinn, director of research and intellectual property at EXFO, “We are delighted to demonstrate that our measurement method, previously only applied to medium distance OTDR-based PMD measurements in a completely different context, can be used through tightly-filtered light paths to characterize link PMD over long-haul distances, thereby opening the door to practical PMD characterization of in-service networks.”

About EXFO
Listed on the NASDAQ and TSX stock exchanges, EXFO is among the leading providers of next-generation test and service assurance solutions for wireless and wireline network operators and equipment manufacturers in the global telecommunications industry. The company offers innovative solutions for the development, installation, management and maintenance of converged, IP fixed and mobile networks — from the core to the edge. Key technologies supported include 3G, 4G/LTE, IMS, Ethernet, OTN, FTTx, and various optical technologies (accounting for an estimated 35% of the portable fiber-optic test market). EXFO has a staff of approximately 1700 people in 25 countries, supporting more than 2000 telecom customers worldwide. For more information, visit

About General Photonics
Founded in 1995, General Photonics is an award-winning world leader in the design and development of advanced optical polarization and timing management instruments, modules and components. Its products are used worldwide in applications such as fiber optic communications networks; test and measurement applications such as for coherent detection systems; fiber optic sensor systems; medical imaging equipment and other applications. General Photonics, a privately-held company, maintains its headquarters and a manufacturing facility in Chino, Calif. An Engineering Center of Excellence and technical support team is located in Beijing, China. The company also uses a worldwide network of sales distributors and representatives. More information can be found at

About Verizon
Verizon Communications Inc. (NYSE, NASDAQ:VZ), headquartered in New York, is a global leader in delivering broadband and other wireless and wireline communications services to mass market, business, government and wholesale customers. Verizon Wireless operates America's most reliable wireless network, serving 94.1 million customers nationwide. Verizon also provides converged communications, information and entertainment services over America's most advanced fiber-optic network, and delivers innovative, seamless business solutions to customers around the world. A Dow 30 company, Verizon employs a diverse workforce of more than 194,000 and last year generated consolidated revenues of $106.6 billion. For more information, visit

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