From the Publisher:
A Unique, Cutting-Edge Approach to Optical Filter Design With more and more information being transmitted over fiber-optic lines, optical filtering has become crucial to the advanced functionality of todays communications networks. Helping researchers and engineers keep pace with this rapidly evolving technology, this book presents digital processing techniques for optical filter design. This higher-level approach focuses on filter characteristics and enables readers to quickly calculate the filter response as well as tackle larger and more complex filters. The authors incorporate numerous theoretical and experimental results from the literature and discuss applications to a variety of systemsincluding the new wavelength division multiplexing (WDM) technology, which is fast becoming the preferred method for system upgrade and expansion. Special features of this book include:
*The theory underlying various architectures that can approximate any filter function
*Filter design techniques applicable to a broad range of materials systemsfrom silica to fiber to microelectromechanical (MEM) systems
*Design examples relevant to filters for WDM systems and planar waveguide devices
*250 figures as well as problem sets for use in graduate-level studies

Optical Filter Design and Analysis: A Signal Processing Approach

We propose a new method to compensate exactly for both chromatic dispersion and self-phase modulation in a transmission fiber, where the light intensity changes due to fiber loss and amplifier gain. This method utilizes optical phase conjugation (OPC). The pulse shape is precompensated before OPC by transmission through a fiber with large dispersion. A computer simulation demonstrates effective compensation for waveform distortion in a 40 Gb/s NRZ intensity-modulated light transmission.

Exact compensation for both chromatic dispersion and Kerr effect in a transmission fiber using optical phase conjugation

Higher order spatial modes in optical fibers exhibit large, negative chromatic dispersion when operated near their cutoff wavelength. By using a spatial mode-converter to selectively excite a higher order mode in specially designed multimode fiber, this dispersion can be used to compensate the positive dispersion in conventional single-mode fiber spans. In this paper, issues related to compensating fiber and mode-converter design are explored. Experimental measurements in specially designed two-mode fibers operated in LP/sub 11/ mode show negative dispersion as large as -70 ps/nm/spl middot/km at 1555 nm. Pulse propagation and system experiments employing spatial mode-converters to excite LP/sub 11/ mode in a two-mode fiber demonstrate the feasibility of this technique for dispersion compensation in lightwave systems. >

Optical fiber-based dispersion compensation using higher order modes near cutoff

Four-wave mixing (FWM) in semiconductor optical amplifiers is an attractive mechanism for wavelength conversion in wavelength-division multiplexed (WDM) systems since it provides modulation format and bit rate transparency over wide tuning ranges. A series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented. Included are single-channel conversion over 18 nm of shift at 10 Gb/s, multichannel conversion, and cascaded conversions. In addition time resolved spectral analysis of wavelength conversion is presented.

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Wavelength conversion for WDM communication systems using four-wave mixing in semiconductor optical amplifiers

We propose the use of a dispersive medium with a negative nonlinear refractive-index coefficient as a way to compensate for the dispersion and the nonlinear effects resulting from pulse propagation in an optical fiber. The undoing of pulse interaction might allow for increased bit rates.

Compensating for dispersion and the nonlinear Kerr effect without phase conjugation

The effective compensation of waveform distortion due to chromatic dispersion in a single-mode fiber was demonstrated using an optical phase-conjugate wave generated by nondegenerate forward four-wave mixing in a zero-dispersion single-mode fiber. After transmission of 5- and 6-Gb/s continuous-phase FSK (CPFSK) signal through a dispersive single-mode fiber, distortion compensation was confirmed by measuring bit error rate characteristics and observing heterodyne-detected eye-patterns. >

T. Naito

Papers

Compensation of chromatic dispersion in a single-mode fiber by optical phase conjugation