PAM-4 Signaling over VCSELs with 0.13μm CMOS Chip Technology

We present results for VCSEL based links operating PAM-4 signaling using a commercial 0.13μm CMOS technology. We perform a complete link analysis of the Bit Error Rate, Q factor, random and deterministic jitter by measuring waterfall curves versus margins in time and amplitude. We demonstrate that VCSEL based PAM–4 can match or even improve performance over binary signaling under conditions of a bandwidth limited, 100meter multi-mode optical link at 5Gbps. We present the first sensitivity measurements for optical PAM-4 and compare it with binary signaling. Measured benefits are reconciled with information theory predictions. ©2006 Optical Society of America OCIS codes: (200.4650) Optical Interconnects; (060.0060) Fiber Optics and Optical Communication References and links 1. R. Farjad-Rad, C.-K. K. Yang and M. A. Horowitz, "A 0.3mm CMOS 8-GS/s 4-PAM Serial Link Transceiver," IEEE J. Solid-State Circuits 35, 757-764, (2000). 2. S. Walkin and J. Conradi, “Multilevel Signaling for increasing the reach of 10Gbps Systems,” J. Lightwave Technol. 17, 2235-2248 (1999). 3. K. Yonenage and S. Kuwano, “Dispersion tolerant optical transmission using doubinary transmitter and binary receiver,” J. Lightwave Technol. 15, 1530-1537, (1997). 4. A. Adamiecki, M. Duelk, J.H. Sinsky, M. Mandich: “Scalability of Duobinary Signaling to 25Gb/s for 100 GbE Applications,” IEEE 802.3ap Task Force Meeting, (November 2004). http://www.ieee802.org/3/ap/public/nov04/adamiecki_01_1104.pdf 5. H. Wu, J. Tiemo, P. Pepeljugoski, J. Schaub,S. Gowda, J. Kask, and A. Hajimir, "Differential 4-tap and 7tap Transverse Filters in SiGe for 10Gh/s Multimode Fiber Optic” Link equalization" 2003 IEEE Intemational Solid State Circuit Conference. pp 180-181, February 2003. 6. David Cunningham, “Multilevel Modulation for 10GbE:Link and Component Specification,” see http://grouper.ieee.org/groups/802/3/10G_study/public/july99/cunningham_1_0799.pdf. 7. C. Pelard, E. Gebara, A. J. Kim, M. Vrazel, E. J. Peddi, V. M. S.Hietala, Bajekal, S. E. Ralph, and J. Laska, “Multilevel signaling and equalization over multimode fiber at 10 Gbit/s,” Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2003. 25th Annual Technical Digest 2003. IEEE, p.197-199, (2003) 8. John. E. Cunningham, David K. McElfresh, Leon D. Lopez, Dan Vacar, and Ashok V. Krishnamoorthy, “Scaling vertical-cavity surface-emitting laser reliability for petascale systems,” Appl. Opt. 45, 6342-6348 (2006). 9. Richard J. S. Bates, Daniel M. Kuchta, Kenneth P. Jackson, "Improved Multimode Fiber Link BER Calculations due to Modal Noise and Non Self-Pulsating Laser Diodes," Opt. Quantum Electron. 27, 203224 (1995). 10. See Sang-Hoon Lee , Yong-Sang Cho , Bon-Jo Koo , Sang-Kook Han, “Optimization of a small to-can package electrical design for SFF/SFP optical transceiver module,” Microwave Opt.l Technol. Lett. 40, 239– 242, (2003). 11. G. P. Agrawal, “Fiber Optics Communication Systems,” 2nd ed., John Wiley and Sons, p. 180-182, (1997). 12. P. Voois, N. Swenson, and T. Lindsay, “Extending the Ethernet Link Model for EDC and Modulation Format,”http://grouper.ieee.org/groups/802/3/10GMMFSG/public/mar04/voois_1_0304.pdf 13. We have not factored in the effects from the CMOS circuitry which could be the dominate source of rms jitter and thereby mask out other components that contribute to this metric. 14. Dawei Huang, “Free Space Optical Interconnect For Computing System– Design, Optimization and Implementation,” PhD Thesis, University of California, San Diego, to be published Dec (2006) #74307 $15.00 USD Received 28 August 2006; revised 21 November 2006; accepted 21 November 2006 (C) 2006 OSA 11 December 2006 / Vol. 14, No. 25 / OPTICS EXPRESS 12028 15. Vladimir Stojanovic, “Channel-Limited High-Speed Links: Modeling, Analysis And Design, PhD Thesis, Stanford University,” 2004 16. Larry A. Coldren and Scott W. Corzine, “Diode Lasers and Photonic Integrated Circuits,” pg 200, John Wiley and Sons (1995) 17. Only small improvement in VCSEL frequency response have developed to date compared with earlier reports of a 21 GHz result dated in 1997. see K. L. Lear, M. Ochiai, V. M. Hietala, H. Q. Hou, B. E. Hammons, J. J. Banas, and J. A. Nevers, “Small and large signal modulation of 850nm oxide-confined vertical-cavity surface-emitting lasers,” Advances in Vertical Cavity Surface Emitting Lasers in Trends in Optics and Photonics Series, 15, 69-74, (1997).