MPN Theory Predictions vs. Measurements. Meir Bartur ZONU, Inc. IEEE ah interim January 2002 Raleigh, NC

Transcription

1 MPN Theory Predictions vs. Measurements Meir Bartur ZONU, Inc. IEEE 8. ah interim January Raleigh, NC

2 MPN theory predictions and test results MPN theory predictions at.5 Gb/s (see Appendix for equations and details. WC stands for worst case for G.65 (SM8) fiber. Different plots for different emitter wavelength. k =, λ is rms db λ =.5 nm λ =.5 nm WC 9nm WC 75nm WC 56nm Fiber IDxx 75nm k = Theoretical curves WC 9nm WC 75nm WC 56nm Fiber IDxx 75nm IEEE 8.ah Jan.

3 MPN theory predictions and test results MPN theory predictions (see Appendix ) k =.5 λ =.5 nm λ =.5 nm WC 9nm WC 75nm WC 56nm Fiber IDxx 75nm k =.5 Theoretical curves WC 9nm WC 75nm WC 56nm Fiber IDxx 75nm IEEE 8.ah Jan.

4 MPN theory predictions and test results MPN theory predictions (see Appendix ) k = (Telcordia) is too pessimistic Others recommend.4 to.5 Our preliminary measurements k <. λ =.5 nm λ =.5 nm WC 9nm WC 8nm WC 5nm Fiber IDxx 75nm k =. Theoretical curves WC 9nm WC 75nm WC 56nm Fiber IDxx 75nm 4

5 MPN test results 5 km (see Appendix for additional conditions) Calc. for Power Margin Analysis Worst case fiber MPN Penalty Worst case assume: Link Budget Loss [db].5.5 nm < λο < nm So =.9 ps/nm /km. Three k values.8,.4,. Measured data (5 km known fiber) k < Wavelength λ =.5 nm S =.86 k=.8 Worst Case (any fiber) k=.4 Worst Case (any fiber) k=. Worst Case (any fiber) Fiber in test ID xxx (k=.) Measurments Measurment Error k=.8 fiber ID xxx k=.4 fiber ID xxx λ =.5nm L = 5 km targetber = B =.5 9 sec ps nm km 5

6 MPN test results 5 km (see Appendix for additional conditions) 4 Worst case fiber MPN Penalty Worst case assume: nm < λο < nm Link Budget Loss [db] So =.9 ps/nm /km. Three k values.8,.4,. Measured data (5 km fiber) k < Wavelength km; k=.8 Worst Case (any fiber) km; k=.4 Worst Case (any fiber) km; k=. Worst Case (any fiber) 5 km; Fiber in test ID xxx (k=.5) Measurments Measurment Error k=5 km;.5 fiber ID xxx 5 km; k=. fiber ID xxx λ =. nm S =.86 λ =.7nm L = targetber = B =.5 9 sec ps nm km LEAST SQUARE FIT: K =.55 6

7 Observations Using worst case k for FP all laser diodes (different manufacturers) is misleading (Power, wavelength, and spectral width are not enough for FP characterization) Need for test methodology, to be used in production, to ensure utilization of FP fo range > km For long reach optics test with km spool of extreme fiber (λο = nm for 4C and λο = nm for 85C) will work. Is it practical? IEEE 8.ah Jan. 7

8 Appendix : Dispersion penalty test setup TEST SET UP FOR MEASURING VARIATIONS IN SENSITIVITY DUE TO CHANGE OF WAVELENGTH FOR A TRANSMITTER WITH A NM TYPE FP LASER Pseudo-Random Pattern Zonu Laser Transmitter inside SUN Systems Environmental chamber Temp. control ONU Zonu Optical Receiver Pseudo-Random Pattern.5 Gbps Bit Error Test Set m SM Fiber m SM Fiber Spool of 5/5km of Corning SMF-8 Fiber m SM Fiber Optical Attenuator EXFO FVA-9A m SM Fiber Agilent 86A Wide-Bandwidth Ocsilloscope m SM Fiber Ando AQ6 Optical Spectrum Analyzer 8

9 Appendix : MPN penalty model equations Agraval et al, "Dispersion Penalty for.um Lightwave Systems," IEEE Journal of Lightwave Technology, Vol.6, No. 5, pp 6-64, May 988 IEEE 8.ah Jan. 9

10 Appendix : Dispersion test conditions Known fiber (5 km for slide 5, 5km for slide 6) Heat/Cool transmitter (the 5 km measurements were done on the cold side only, RT to 7C. The 5 km measurements were done 4C to 7C no corrections to other loss penalty from jitter and rise/fall time all sensitivity losses attributed to dispersion). Test conditions (see also slide 6): different LD (MQW FP lasers) different lots ER constant λ..8 nm rms (only one point <.5 nm).5 Gb/s BER < 5 x - Pattern 7 Known parameters fiber IEEE 8.ah Jan.