Single-Mode Optical Fiber Communication

Our theoretical and experimental research addresses modulation and detection techniques for high spectral efficiency and robustness against transmission impairments in dense wavelength-division-multiplexed (DWDM) systems. This work will help enable next-generation 100 Gb/s long-haul systems using either single-carrier modulation (such as quaternary phase-shift keying, QPSK) or multi-carrier modulation (orthogonal frequency-divsion multiplexing, OFDM). Over two decades, we have performed extensive research on coherent optical detection. In the late 1980s, we demonstrated the first optical phase-locked loop using semiconductor lasers, and built BPSK homodyne transmission links that achieved world-record receiver sensitivities (46 photons/bit at 1 Gb/s and 72 photons/bit at 4 Gb/s). In 1992, we demonstrated coherent detection of QPSK, a technique offering high spectral efficiency and high receiver sensitivity. More recently, we have been studying adaptive digital signal processing techniques to compensate transmission impairments. These include linear effects, such as chromatic dispersion and polarization-mode dispersion, as well as nonlinear effects, including intra-channel four-wave mixing and nonlinear phase noise. We are also studying carrier phase-syncronization methods. Finally, we have performed extensive research on fundamental spectral efficiency limits dictated by information theory.

Coherent Systems

E. Ip, A. P. T. Lau, D. J. F. Barros and J. M. Kahn, "Coherent Detection in Optical Fiber Systems", Optics Express, vol. 16, no. 2, pp. 753-791, January 21, 2008 (Invited Paper). PDF

E. Ip and J. M. Kahn, "Compensation of Dispersion and Nonlinear Effects using Digital Backpropagation", subm. to J. of Lightwave Technol., March 2008.

D. J. F. Barros and J. M. Kahn, "Optimized Dispersion Compensation Using Orthogonal Frequency-Division Multiplexing", to be published in J. of Lightwave Technol.. PDF

A. P. T. Lau, S. Rabbani and J. M. Kahn, "On the Statistics of Intra-Channel Four-Wave Mixing in Phase-Modulated Optical Communication Systems", to be published in J. of Lightwave Technol. PDF

A. P. T. Lau and J. M. Kahn, "Signal Design and Detection in Presence of Nonlinear Phase Noise", J. of Lightwave Technol., vol. 25, no. 10, pp. 3008-3016, October 2007. PDF

E. Ip and J. M. Kahn, "Feedforward Carrier Recovery for Coherent Optical Communications", J. of Lightwave Technol., vol. 25, no. 9, pp. 2675-2692, September 2007. PDF

E. Ip and J. M. Kahn, "Digital Equalization of Chromatic Dispersion and Polarization Mode Dispersion", J. of Lightwave Technol., vol. 25, no. 8, pp. 2033-2043, August 2007. PDF

J. M. Kahn, "Modulation and Detection Techniques for Optical Communication Systems", Proc. of OSA Topical Meeting on Coherent Optical Technologies and Applications, Whistler, BC, June 28-30, 2006 (Invited Paper). PDF

E. Ip and J. M. Kahn, "Carrier Synchronization for 3- and 4-bit-per-Symbol Optical Transmission", J. of Lightwave Technol., vol. 23, no. 12, pp. 4110-4124, December 2005. PDF

E. Ip, J. M. Kahn, D. Anthon and J. Hutchins, "Linewidth Measurements of MEMS-Based Tunable Lasers for Phase-Locking Applications", IEEE Photon. Technol. Lett., vol. 17, no. 10, pp. 2029-2031, October 2005. PDF

J. M. Kahn, A. M. Porter and U. Padan, "Heterodyne Detection of 310-Mb/s Quadriphase-Shift Keying Using Fourth-Power Optical Phase-Locked Loop", IEEE Photon. Technol. Lett., vol. 4, pp. 1397-1400, 1992. PDF

J. R. Barry and J. M. Kahn, "Carrier Synchronization for Homodyne and Heterodyne Detection of Optical Quadriphase-Shift Keying", J. Lightwave Technol., vol. 10, pp. 1939-1951, 1992. PDF

J. M. Kahn, A. H. Gnauck, J. J. Veselka, S. K. Korotky and B. L. Kasper, "4 Gbit/s PSK Homodyne Transmission System Using Phase-Locked Semiconductor Lasers," IEEE Photon. Technol. Lett., vol. 2, pp. 285-287, 1990. PDF

J. M. Kahn, "1 Gbit/s PSK Homodyne Transmission System Using Phase-Locked Semiconductor Lasers," IEEE Photon. Technol. Lett., vol. 1, pp. 340-342, 1989.

J. M. Kahn, C. A. Burrus and G. Raybon, "High-Stability 1.5 Micron External-Cavity Lasers for Phase-Lock Applications," IEEE Photon. Technol. Lett., vol. 1, pp. 159-161, 1989. PDF

J. M. Kahn and B. L. Kasper, "Optical Phaselock Receiver with Multi-Gigahertz Signal Bandwidth", Electron. Lett. vol. 25, pp. 626-627, 1989.

Spectral Efficiency Limits

J. M. Kahn and K.-P. Ho, "Spectral Efficiency Limits and Modulation/Detection Techniques for DWDM Systems", IEEE. J. on Sel. Topics in Quantum Electron., vol. 10, no. 2, pp. 259-272, March/April 2004 (Invited Paper). PDF

J. M. Kahn and K.-P. Ho, "Ultimate Spectral Efficiency Limits in DWDM Systems", Proc. of OptoElectronics and Communications Conference, Yokohama, Japan, July 8-12, 2002 (Invited Paper). PDF

K.-P. Ho and J. M. Kahn, "Channel Capacity of WDM Systems Using Constant-Intensity Modulation Formats", Proc. of Optical Fiber Commun. Conf., Anaheim, CA, March 17-22, 2002. PDF

J. M. Kahn and K.-P. Ho, "A Bottleneck for Optical Fibres", Nature, vol. 411, pp. 1007-1010, June 28, 2001 (Invited Paper). PDF Also see this related paper by Mitra and Stark: PDF

Linear and Nonlinear Impairments: Impact and Compensation Techniques

E. Ip and J. M. Kahn, "Compensation of Dispersion and Nonlinear Effects using Digital Backpropagation", subm. to J. of Lightwave Technol., March 2008.

D. J. F. Barros and J. M. Kahn, "Optimized Dispersion Compensation Using Orthogonal Frequency-Division Multiplexing", to be published in J. of Lightwave Technol.. PDF

A. P. T. Lau, S. Rabbani and J. M. Kahn, "On the Statistics of Intra-Channel Four-Wave Mixing in Phase-Modulated Optical Communication Systems", to be published in J. of Lightwave Technol. PDF

A. P. T. Lau and J. M. Kahn, "Signal Design and Detection in Presence of Nonlinear Phase Noise", J. of Lightwave Technol., vol. 25, no. 10, pp. 3008-3016, October 2007. PDF

A. P. T. Lau and J. M. Kahn, "Power Profile Optimization in Phase-Modulated Systems in Presence of Nonlinear Phase Noise", IEEE Photon. Technol. Lett., vol. 18, no. 23, pp. 2514-2516, December 1, 2006. PDF

E. Ip and J. M. Kahn, "Digital Equalization of Chromatic Dispersion and Polarization Mode Dispersion", J. of Lightwave Technol., vol. 25, no. 8, pp. 2033-2043, August 2007 PDF

A. P. T. Lau and J. M. Kahn, "Design of Inline Amplifier Gains and Spacings to Minimize Phase Noise in Optical Transmission Systems", J. of Lightwave Technol., vol. 24, no. 3, pp. 1334-1341, March 2006. PDF

J. Wang and J. M. Kahn, "Accurate Bit-Error Ratio Computation in Nonlinear CRZ-OOK and CRZ-DPSK Systems", IEEE Photon. Technol. Lett., vol. 16, no. 9, pp. 2165-2167, September 2004. PDF

J. Wang and J. M. Kahn, "Conventional DPSK vs. Symmetrical DPSK: Comparison of Dispersion Tolerances", IEEE Photon. Technol. Lett., vol. 16, no. 6, pp. 1585-1587, June 2004. PDF

J. Wang and J. M. Kahn, "Performance of Electrical Equalizers in Optically Amplified OOK and DPSK Systems", IEEE Photon. Technol. Lett., vol. 16, no. 5, pp. 1397-1399, May 2004. PDF

K.-P. Ho and J. M. Kahn, "Electronic Compensation Technique to Mitigate Nonlinear Phase Noise", J. of Lightwave Technol., vol. 22, no. 3, pp. 779-783, March 2004. PDF

J. Wang and J. M. Kahn, "Impact of Chromatic and Polarization-Mode Dispersions on DPSK Systems using Interferometric Demodulation and Direct Detection", J. of Lightwave Technol., vol. 22, no. 2, pp. 362-371, February 2004. PDF

Coding and Modulation Techniques

E. Ip and J. M. Kahn, "Power Spectra of Return-to-Zero Optical Signals", J. of Lightwave Technol., vol. 24, no. 3, pp. 1610-1618, March 2006. PDF

W. Mao and J. M. Kahn, "Lattice Codes for Amplified Direct-Detection Optical Systems", to be published in IEEE Trans. on Commun. PDF

K.-P. Ho and J. M. Kahn, "Spectrum of Externally Modulated Optical Signals", J. of Lightwave Technol., vol. 22, no. 2, pp. 658-663, February 2004. PDF

T. Ohtsuki and J. M. Kahn, "Bit-Error Rate Performance of Turbo-Coded PPM CDMA Systems on Optical Fiber", J. Lightwave Technol., vol. 18, pp. 1776-1784, December 2000. PDF

D. Shiu and J. M. Kahn, "Shaping and Non-Equiprobable Signaling for Intensity Modulated Signals", IEEE Trans. on Information Theory, vol. 45, pp. 2661-2668, November 1999. PDF

Subcarrier-Multiplexed Systems

R. You and J. M. Kahn, "Upper-Bounding the Capacity of Optical IM/DD Channels with Multiple-Subcarrier Modulation and Fixed Bias using Trigonometric Moment Space Method", IEEE Trans. on Info. Theory, vol. 48, pp. 514-523, February 2002. PDF

R. You and J. M. Kahn, "Average Power Reduction Techniques for Multiple-Subcarrier Intensity-Modulated Optical Signals", IEEE Trans. on Commun., vol. 49, pp. 2164-2171, December 2001. PDF

K.-P. Ho and J. M. Kahn, "Optimal Predistortion of Gaussian Inputs for Clipping Channels", IEEE Trans. on Commun., vol. 44, no. 11, pp. 1505-1513, November 1996.

K.-P. Ho and J. M. Kahn, "On Models of Clipping Distortion for Lightwave CATV Systems", IEEE Photon. Technol. Lett., vol. 8, no. 1, pp. 125-126, January 1996.

K.-P Ho and J. M. Kahn, "Equalization Technique to Reduce Laser Clipping-Induced Distortion in Subcarrier-Multiplexed Lightwave Systems", IEEE Photon. Technol. Lett., vol. 5, no. 9, pp. 1100-1103, September 1993.

Wavelength-Division Multiplexed Systems

K.-P. Ho and J. M. Kahn, "Methods for Crosstalk Measurement and Reduction in Dense WDM Systems", J. Lightwave Technol., vol. 14., pp. 1127-1135, June 1996.

K.-P. Ho and J. M. Kahn, "Optical Frequency Comb Generator Using Phase Modulation in Amplified Circulating Loop", IEEE Photon. Technol. Lett., vol. 5, no. 6, pp. 721-725, June 1993.

All-Optical Networks

X. Zhu and J. M. Kahn, "Queueing Models of Optical Delay Lines in Synchronous and Asynchronous Optical Packet-Switching Networks", Optical Engineering, vol.42, no.6, pp.1741-1748, June 2003. PDF

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Last modified: April 15, 2008.