Dec 12 2007
JDSU today announced improved measurement analysis for its industry-leading in-band optical spectrum analyzer (OSA) for the T-BERD/MTS-8000. The OSA-320 module, a high-performance optical spectrum analyzer, incorporates a unique and highly accurate method for measuring the "true" optical signal-to-noise ratio (OSNR) in Reconfigurable Optical Add/Drop Multiplexer (ROADM) networks.
The JDSU OSA-320 module was engineered to test optical performance in the Agile Optical Network (AON), a dynamically reconfigurable DWDM network that is designed to accelerate triple-play service deployment, simplify network management, and enable advanced wavelength applications at significantly reduced costs.
In the AON, multiple ROADMs with different "filtering" technologies can be cascaded in a link, creating OSNR measurement problems for conventional OSA devices that employ out-of-band methods. Even the most recent OSA devices using the "shoulder method" may not provide accurate OSNR results for different ROADM filter shapes at high data rates. With JDSU's improved measurement analysis it is possible to accurately measure the "true" OSNR in all deployment scenarios of ROADM networks (from 10G to 40G), regardless of the filter type integrated into the ROADM.
"The new measurement algorithm for the JDSU OSA-320 helps address a major challenge in testing ROADM networks," said Enzo di Luigi, general manager of JDSU's fiber optics Communications Test and Measurement group. "Accurately measuring OSNR requires a strong understanding of ROADM network components and architectures, and JDSU is uniquely positioned among test equipment providers to leverage optical leadership in the ROADM market, including active and passive components and network solutions, allowing us to bring smarter ROADM test solutions to market faster."
In ROADM networks, each channel may traverse different routes, optical amplifiers, and add-drop filters, resulting in different OSNR for each channel. Conventional OSA measurements are unreliable, as they indicate OSNR values that are too high -- up to 10dB above the true OSNR. JDSU's OSA-320 follows an optical polarization splitting (OPS) method for measuring OSNR inside the optical channel (in-band OSNR), providing the highly accurate, "true" OSNR.