Highly accurate, easy-to-use intelligent optical spectrum analyzers (OSAs) for current and next-generation networks.
Unique Pol-Mux OSNR measurement technology
OSNR has long been recognized as a key performance indicator in wavelength-division multiplexing (WDM) networks, because it provides a multichannel assessment of signal quality in a very short period of time. In addition, OSNR can predict bit error rate (BER) within just a few minutes, while typical BER tests must run for hours or days.
The IEC 61280-2-9 standard defines OSNR measurement as the power ratio between the signal power and the noise at half the distance between the peaks. However, in ROADM or 40 Gbit/s systems, this method may lead to incorrect results, because the noise level between the peaks is no longer directly correlated with the noise level at the channel wavelength. EXFO’s in-band OSNR is the answer to this challenge.
For Pol-Mux signals at 40G and 100G, neither the IEC nor the in-band method work. This calls for a new measurement method: Pol-Mux OSNR.
First Pol-Mux OSA on the market
EXFO’s Pol-Mux OSA is the first third-party instrument for Pol-Mux OSNR measurements that is not limited to any specific system vendor. The new commissioning assistant, which is the key feature of the new Pol-Mux OSA, is perfect for Pol-Mux OSNR measurements during turn-up. Based on the channel shutdown method, it provides highly accurate amplified spontaneous emission (ASE) OSNR measurements.
The commissioning assistant can be utilized after the user has first taken a measurement at the receiver with all of the channels turned on, and then acquired a series of traces, each taken with one channel turned off. The Pol-Mux OSA then performs the Pol-Mux OSNR calculations via a user-friendly wizard.
The commissioning assistant therefore greatly accelerates OSNR measurements based on the channel shutdown method, and drastically reduces potential human errors. In addition, two standards-compliant calculation approaches are available in the commissioning assistant: one compliant with the IEC-61282-12 standard (under revision), and the other compliant with the China Communications Standards Association (CCSA) method YD/T 2147-2010.