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Photo file: 
photograph of Stephen Ralph
Full name: 
Stephen E Ralph
Job title: 
; Director, Georgia Electronic Design Center; Glen Robinson Chair in Electro-Optics
Technical Interest Groups: Nanotechnology, Optics and Photonics, Electromagnetics
Email address: 
TSRB 505

Stephen E. Ralph is a Professor with the School of Electrical and Computer Engineering at Georgia Tech. He received the BEE degree in Electrical Engineering with highest honors from the Georgia Institute of Technology in 1980. He received a Ph.D. in Electrical Engineering from Cornell University in 1988 for his work on highly nonequilibrium carrier transport in semiconductor devices.

He is currently the director of the Georgia Electronic Design Center, a cross-disciplinary electronics and photonics research center focused on the synergistic development of high-speed electronic components and signal processing to enable revolutionary system performance. He is also the founder and director of the new Terabit Optical Networking Consortium, an industry led communications and information technology consortium.

Prior to Georgia Tech he held a postdoctoral position at AT&T Bell Laboratories and was a visiting scientist with the Optical Sciences Laboratory at the IBM T. J. Watson research center.

He has published more than 320 peer-reviewed journals and conference proceedings and holds 14 patents in the fields of optical communications, optical devices, and signal processing. Professor Ralph has mentored more than 20 Ph.D. students. His current research focus is on high capacity optical systems and interconnects, particularly the intersection of electronics, photonics, and signal processing/machine learning and where integrated photonics is a key area of innovation. Professor Ralph is an elected member of the IEEE Photonics Society Board of Governors and is a Fellow of the Optical Society (OSA).

Research interests: 
  • Integrated photonics
  • Machine learning and signal processing
  • Photonics in aerospace applications
  • Ultra high capacity optical communication systems
  • Simulation and modeling of communication systems
  • Fellow of the Optical Society (OSA)
  • Senior Member: Institute of Electrical and Electronic Engineers (IEEE)

J. Pan, C. Liu, T. Detwiler, A. J. Stark, Y.-T. Hsueh, S. E. Ralph, "Inter-Channel Crosstalk Cancellation for Nyquist-WDM Superchannel Applications" J. Light. Technol., v 30, n 24, p3993-99, 15 Dec. 2012.

Y.-T. Hsueh, A. Stark, C. Liu, T. Detwiler, S. Tibuleac, M. Filer, G.-K. Chang, and S. E. Ralph, "Passband Narrowing and Crosstalk Impairments in ROADM-Enabled 100G DWDM Networks," J. Light. Technol., v 30, n24, p3980-86, 15 Dec, 2012.

"Signal processing and Impairments in Next-Generation MMF links," Avionics, Fiber-Optics and Photonics Conference (AVFOP 2012), Cocoa Beach, FL, 11-13 September, 2012. (invited talk)

A. J. Stark, Y.-T. Hsueh, S. Searcy, T. Detwiler, C. Liu, M. Filer S. Tibuleac, GK Chang, and S. E. Ralph, "Scaling 112 Gb/s Optical Networks with the Nonlinear Threshold Metric," J. Light. Technol., v30, n9, p 1291-8, 1 May 2012.

T. F. Detwiler, S. M. Searcy, S. E. Ralph, and E. B. Basch, "Continuous phase modulation for fiber optics links," J. Light. Technol., v 29, n 24, p 3659-71, 15 Dec. 2011.

"25G POF Links," International Conference on Advanced Photonic Polymers (ICAPP), Dec 2-3, 2011, Yokohama, Japan. (invited talk)

"VCSEL-based 100m 25Gb/s Plastic Optical Fiber Links," POF World 2011, Nov. 8-10 Santa Clara, California. (invited talk)

"25G VCSEL-based GI-POF Links," 20th International Conference on Plastic Optical Fibers, Bilbao, Spain, 14-16 September, 2011. (invited talk)

"25G short reach links," 2011 Advanced Photonics Congress, Access Networks and In-house Communications (ANIC), OSA, June 12-15 2011, Toronto, Canada. (invited talk)

Y.-T. Hsueh, A. J. Stark, M. Filer, T. Detwiler, S. Tibuleac, GK Chang, and S. E. Ralph, "In-band Crosstalk Transmission Penalties on 112 Gb/s PDM-QPSK Optical Links," Phot. Tech. Lett. V23, pp.745-747, June, 2011.

P. J. Decker, A. Polley, J. H. Kim, and S. E. Ralph, "Statistical Study of Graded-Index Perfluorinated Plastic Optical Fiber," J. Light. Technol, Vol. 29, pp. 305-315, 2011.

"100 m, 40 Gb/s Plastic Optical Fiber Link," A. Polley, S. E. Ralph, Optical Fiber communication/National Fiber Optic Engineers Conference, 24-28 Feb, 2008. (invited talk)

"High Data Rate Multimode Fiber Access Systems" Lasers and Electro-Optics Society (LEOS), Lake Buena Vista FL. ThDD1, pp. 95, October 21-25, 2007. (invited talk)

A. Polley, K. Balemarthy and S. E. Ralph, "Mode coupling in plastic optical fiber enables 40Gbps performance," Photonics Tech. Letters, Vol. 19, p 1254-6, August 2007.

A. Polley and S. E. Ralph, "Raman amplification in multi-mode fiber," Photonics Tech. Letters, Vol.19, pp.218-220, Feb. 2007.

K. Balemarthy, A. Polley and S. E. Ralph, "Electronic equalization of multi-km 10 Gb/s multi-mode fiber links: Mode coupling effects," J. Light. Technol., Vol. 24, pp. 4885-4894, December 2006.

K. M. Patel, A. Polley, K. Balemarthy and S. E. Ralph, "Spatially resolved detection and equalization of modal dispersion limited multimode fiber links: Electrical signal processing technique," J. Light. Technol., Vol. 24, pp. 2629-2636, July 2006.

J. J. Lillie, M. A. Thomas, K. A. Dennis, N. Jokerst, C. L. Henderson and S. E. Ralph, "Multimode interferometric sensors-on-silicon optimized for fully integrated CMOS chem/bio sensor systems," J. Opt. Soc. Amer. B, Vol. 23, pp. 642-651, April 2006.

J. H. Kim, A. Polley, and S. E. Ralph, "Efficient photoconductive THz source using line excitation," Opt. Lett., Vol. 30, no. 18, pp. 2490-2492, October 2005.

J. S. Rodgers, R. P. Kenan and S. E. Ralph, "Transformation from a multimode interference solution to a self-guiding solution," J. Opt. Soc. Amer. B, Vol. 22, no. 5, pp. 1037-1044, May 2005.

C. Pelard, E. Gebara, A. J. Kim, M. G. Vrazel, F. Bien, Y. Hur, M. Maeng, S. Chandramouli, C. Chun, S. Bajekal, S. E. Ralph, B. Schmukler, V. M. Hietala and J. Laskar, "Realization of multigigabit channel equalization and crosstalk cancellation integrated circuits," IEEE J. of Solid Sate Circuits, Vol. 39, pp. 1659-1670, 2004.

C. Argon, K. M. Patel, S. W. McLaughlin and S. Ralph, "Exploiting diversity in multimode fiber communications links via multisegment detectors and equalization," Communications Lett., IEEE, Vol. 7, pp. 400-402, August 2003.

M. C. Gross, M. Hanna, K. M. Patel, and S. E. Ralph, "Reduction of power fluctuations in ultrafast optically time-division-multiplexed pulse trains by use of a nonlinear amplifying loop mirror," Photon. Technol. Lett., Vol. 14, pp.690-692, May 2002.

M. C. Gross, M. Hanna, K. M. Patel and S. E. Ralph, "Spectral method for the simultaneous determination of uncorrelated and correlated amplitude and timing jitter," Appl. Phys. Lett., Vol. 80, pp. 3694-6, May 2002.

K. Patel and S. E. Ralph, "Enhanced multimode fiber link performance using a spatially resolved receiver," Photon. Technol. Lett., Vol. 14, pp.393-395, March 2002.

B. R. Washburn, S. E. Ralph, P. A. Lacourt, J. M. Dudley, W. T. Rhodes, S. Coen and R. S. Windeler, "Femtosecond soliton generation in photonic crystal fibers," Electron. Lett., Vol. 37, pp. 1510-1512, 2001.

T. G. Ulmer, P. Juodawlkis, M. C. Gross, K. M. Patel, J. T. Simmons, B. R. Washburn, W. S. Astar, A. J. SpringThorpe, R. P. Kenan, C. M. Verber and S. E. Ralph, "160-Gb/s optical time-division multiplexed link with all-optical demultiplexing," (Special Issue on Optical Networking); J. Light. Technol., Vol. 18, pp. 1964-1977, 2000.

Last revised August 31, 2020