Channel Isolation for Data Rates up to 10.7 Gb/s OSA Modules By Peter Winterling

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1 Application Note Channel Isolation for Data Rates up to 10.7 Gb/s OSA Modules By Peter Winterling Introduction The quality of service in a connection can be determined via end-to-end measurements just as with DWDM systems. Gaining access to individual channels within a DWDM system for trouble shooting is not possible in the field as only the complete DWDM signal is available at the EDFA amplifier monitoring point. In such a case, only the optical signal-tonoise-ratio (OSNR), optical power and wavelength of each channel can be measured but not the quality of service. The OSA Optical spectrum analyzers (OSA) can only determine scalar values. That is to say only OSNR, wavelength and optical power values can be measured in DWDM systems. These parameters are vulnerable particularly in channel balancing. Additional linear and non-linear effects such as dispersion, four wave mixing and cross talk can not be detected by OSAs making bit error measurement all the more important as a final test procedure. MUX DCM DEMUX WEBSITE:

2 Application Note: Optical Spectrum Analyzer Module 2 Test Solution The JDSU OSA modules OSA-161/OSA-201 and OSA-301/303 enable the separation or drop of individual channels from a DWDM signal. The development of new technology and use of completely different optical functionalities has made the isolation of a single channel with a data rate up to 10.7 Gbps and not exceeding 100 pm for the measuring path a reality. MUX DCM DEMUX BERT or Q-Factor Background Information The optical spectrum analyzer is based on the principle of a monochromator. This provides outstanding performance for measurement purposes in DWDM systems down to 25 GHz spacing. The filter bandwith for analysis should be below 100 pm to deliver optimum design and a workable compromise between dynamic, resolution and sensitivity.

3 Application Note: Optical Spectrum Analyzer Module 3 Center wavelength e.g nm Signal form 2.5 Gbps 10 GHz el. BW ~ 80 pm opt. BW Signal form 10 Gbps -30 GHz -20 GHz -10 GHz +10 GHz +20 GHz +30 GHz Filter width 220 pm (OSA-161) Filter width 80 pm (OSA-155) Realization Different OSA modules are available for hte ONT mainframes as well as for the MTS/T-BERD 8000 platform: Full-band OSA modules: OSA-161: Single port with drop OSA-201: Dual port with drop High-performance OSA modules: OSA-301: Single port with drop OSA-303: Dual port with drop

4 Application Note: Optical Spectrum Analyzer Module 4 Operation Channel isolation set up Select Drop in the main menu. All channels are then listed in a table. Select and copy the required channel upon which the drop-function is to be performed. Channel isolation mode can be activated at the touch of a button. Tracking function If a frequency is selected once, using the tracking function will enable the filter to follow all drifting effects on the selected wavelength. Conversely, the tracking function can also be used to ensure that the selected wavelength is symmetrically isolated. Tracking function Other products around this application EDFA amplifier JDSU M-200 as a module for ONT-50 Often there is a need for an optical amplifier as the power at the optical amplifier monitor point can often lie below 20 db. The OSA-161/-201 and OSA-301/303 contain a certain amount of insertion loss. To allow SONET/SDH analysis on an isolated signal, the signal must be re-amplified. JDSU s one-slot optical amplifier module (M) available on the ONT- 50 mainframe (see application note Using optical amplifiers to determine quality ofservicd in phtoonic newtwoks ) is equipped to carry out this task. SONET/SDH module for the test platform ONT-50 JDSU provides a broad portfolio of test modules for SONET/SDH measurements encompassing SDH, SONET, OTN, New SDH, and Jitter applications.

5 Application Note: Optical Spectrum Analyzer Module 5 Q-factor analyzer The Q-factor analyzer is a new tool for testing DWDM systems. In a worldwide industry first, JDSU provided the first field tester for the analysis of quality of service in optical signals. The tester was able to produce result in under a minute as opposed to the standard ten hour bit error testing to fulfil ITU recommendations.

6 Application Note: Optical Spectrum Analyzer Module 6 Available literature Datasheets & Brochures Datasheet ONT-30 Datasheet ONT-50 Datasheet ONT-506/512 White Papers Remote Access Optimizing Resources for Optical Transport and DWDM Measurements by Hans-Werner Schaal DWDM - Messtechnik von heute für DWDM-Übertragungssysteme für morgen by Peter Winterling Publications Funkschau 52/2002: Photonische Netze schneller testen c t Magazin für Computertechnik, 3/2003: Optische Netze Technik, Trends und Perspektiven Specialist books Technik und Troubleshooting in optischen Netzen DWDM, SDH & Co von Kiefer/Winterling Hüthig Verlag, ISBN Price 44 EUR All statements, technical information and recommendations related to the products herein are based upon information believed to be reliable or accurate. However, the accuracy or completeness thereof is not guaranteed, and no responsibility is assumed for any inaccuracies. The user assumes all risks and liability whatsoever in connection with the use of a product or its applications. JDSU reserves the right to change at any time without notice the design, specifications, function, fit or form of its products described herein, including withdrawal at any time of a product offered for sale herein. JDSU makes no representations that the products herein are free from any intellectual property claims of others. Please contact JDSU for more information. JDSU and the JDSU logo are trademarks of JDS Uniphase Corporation. Other trademarks are the property of their respective holders JDS Uniphase Corporation. All rights reserved ONT30OSA.AN.FOP.TM.AE Test & Measurement Regional Sales NORTH AMERICA TEL: FAX: LATIN AMERICA TEL: FAX: ASIA PACIFIC TEL: FAX: EMEA TEL: FAX: WEBSITE: