Optical Communications & Networking

Optical fiber is being extended directly into office buildings and business parks, where the concentration of users of large volume traffic is high.  An emerging challenge is the extension of fiber into the access network in small business and residential areas. Once this happens, more functions will be transferred to the optical layer. Advanced processing will be invoked to achieve fast re-configurable networks. New network paradigms will be needed, involving restructuring the periphery to extend all-optical techniques and optical switching from the backbone into the local area. This has implications for new devices and techniques including optical switches, data formats, and new networking protocols. An important network issue involves the optical-wireless interface and techniques to provide wireless access over the optical bandwidth involving a seamless hybridization and integration of microwave wireless signals with the optical backbone.

Concentration of research is on Wavelength Division Multiplexing (WDM) and Code Division Multiplexing (CDM) in optical networks and systems.

Some past contributions in this area:

  • N. Tayebi, M. Kavehrad, "Laser Nonlinearity Compensation for Radio Sub-carrier Multiplexed Fiber Optic Transmission Systems, "IEICE Trans. on Communications (Japan), No. 9, September 1993. "INVITED PAPER".
  • H. Ohtsuka, O. Kagami, S. Komaki, K. Kohiyama, M. Kavehrad, "256-QAM Sub-carrier Transmission Using Coding and Optical Intensity Modulation in Distribution Networks," IEEE/LEOS Photonics Technology Letters, April 1991.
  • M. Kavehrad, E. Savov, "Fiber-Optic Transmission of Microwave 64-QAM Signals," IEEE Journal on Selected Areas in Communications, Vol. 8, No. 7, Sept. 1990, pp. 1320-1326.
  • M. Kavehrad, B. Glance, "Polarization-Insensitive Frequency Shift Keying Optical Heterodyne Receiver using Discriminator Demodulation," IEEE Journal of Lightwave Technology, Vol. LT-6, No. 9, September 1988, pp. 1388-1394.
  • M. Kavehrad, "Wavelength-Division Multiplexed Systems and Networks," IEEE/LEOS'93, Annual Meeting, San Jose, Nov. 1993 - "INVITED PAPER".
  • F. Ayadi, J.F. Hayes, M. Kavehrad, "WDM Cross-Connected Star Topology for the Bi-layered Shuffle-Net," IEEE Jour. of Lightwave Tech., Vol. 12, No. 9, Sept. 1994.
  • G.N.M. Sudhakar, M. Kavehrad, N.D. Georganas, "Access Protocols for Passive Optical Star Networks," Computer Networks and ISDN Systems, Vol. 26, March 1994.
  • M.I. Irshid, M. Kavehrad, "A WDM Cross-Connected Star Topology for Multihop Lightwave Networks," IEEE/OSA Journal of Lightwave Tech., Vol. 10, No. 6, June 1992.
  • M. I. Irshid, M. Kavehrad, "A Fully Transparent Fiber-Optic Ring Architecture for WDM Networks," IEEE/OSA Journal of Lightwave Technology, Vol. 10, NO. 1, January 1992, pp. 101-108.
  • G.N.M. Sudhakar, N.D. Georganas, M. Kavehrad, "Slotted Aloha and Reservation Aloha Protocols for Very High-Speed Optical Fiber Local Area Networks Using Passive Star Topology," IEEE/OSA Journal of Lightwave Technology, October 1991, pp. 1411-1422.
  • H. Shi, M. Kavehrad, "ALOHA/Slotted-CSMA Protocol for a Very High-Speed Optical Fiber Local Area Network Using Passive Star Topology," Proceedings of IEEE INFOCOM Conference, Florida, April 1991.
  • I. Habbab, M. Kavehrad and C-E. Sundberg, "Protocols for Very High Speed Optical Fiber Local Area Networks using a Passive Star Topology," IEEE Journal of Lightwave Technology, Vol. LT-5, No. 12, December 1987, pp. 1782-1794 and ICC Proceedings, Seattle, June 1987.
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Optical Network Subsystems

Design and performance analyses of passive optical components, e.g., broadcast and selective-broadcast star couplers, grating mux/demux, wavelength routers, grating spectral encoders and diffusers.

Laser modeling and characterization.

Erbium-Doped Fiber Amplifiers modeling, analysis, design and implementation.

Optical Grating Components

Dr. Eli Simova, Research Associate, demonstrates holographic coupling.

 

United States Patents

Related Papers

  • E. Simova, M. Kavehrad,"Light Shaping Diffusers for Indoor Wireless Infrared Communications via a Holographic Approach," Proceedings of SPIE Photonics West'96, San Jose, California, February 1996.
  • E. Simova, M. Kavehrad, K. Stoev, "Wavelength Demultiplexing by Chirped Waveguide Gratings," Optics Communications Jour., Vol. 134, Jan. 1997.
  • M. Tabiani, M. Kavehrad, M. Irshid, "A Novel Integrated-Optic WDM Cross-Connect for Wide Area All Optical Networks," IEEE/OSA Journal of Lightwave Tech., Vol. 11, No. 3, March 1993.
  • G. Yun, M. Kavehrad, "Grating Degeneration Technique and Sandwich Structures for Holographic NXN Passive Star Couplers," IEEE/OSA Journal of Lightwave Technology, Vol. 10, No. 11, Nov. 1992.
  • M.I. Irshid, M. Kavehrad, "Star Couplers with Gain Using Fiber Amplifiers," IEEE/LEOS Photonics Technology Letters, Vol. 4, No. 1, January 1992, pp. 58-60.
  • M. Kavehrad, M. Tabiani, "A Selective-Broadcast Passive Star Coupler for Self-Routing Dense Wavelength Division Multiplexed Optical Networks," IEEE/OSA of Lightwave Technology, Vol. 9, No. 10, October 1991, pp. 1278-1288.
  • M. Tabiani, M. Kavehrad, "Theory of an Efficient N X N Passive Optical Star Coupler," IEEE /OSA Journal of Lightwave Technology, April 1991.

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Optical Cross-Connects

Design, performance analyses and comparison of Wavelength Division Multiplexed, Space Division Multiplexed (SDM), Code Division Multiplexed and Hybrid WDM/SDM optical cross-connect systems.


United States Patents

Related Papers

  • Y.D. Jin, M. Kavehrad,"An Optical Cross-Connect System as a High-Speed Switching Core and Its Performance Analysis," IEEE Jour. of Lightwave Tech., Vol. 14, No. 6, June 1996 and IEEE/LEOS Summer Topical Meeting Digest, Colorado, August 1995.

WDM Active Routing Architecture

Optical Cross-Connect based on WDM and Space Division Multiplexing

Optical Cross-Connect

An 8x8 Optical Cross-Connect

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