Quasi-Analytic Synthesis of Nonrecursive Optical Delay Line Filters for Reliable Compensation of Dispersion Effects

• Published in: Journal of lightwave technology Vol. 24; no. 11; pp. 4403 - 4410
• Main Authors: Duthel, T., Fritzsche, D., Michael, F., Schaffer, C.G., Breuer, D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Applied sciences; Channels; Circuit properties; Compensation; Control system synthesis; Delay lines; Detection, estimation, filtering, equalization, prediction; Dispersion; Dispersions; Electric, optical and optoelectronic circuits; Electronics; equalization; Exact sciences and technology; finite-impulse response (FIR) digital filters; High speed optical techniques; Information, signal and communications theory; Integrated optics. Optical fibers and wave guides; Iterative algorithms; Linear approximation; Mathematical analysis; Nonlinear filters; Optical and optoelectronic circuits; optical fiber dispersion; Optical filters; Optical telecommunications; Optimization; phase distortion; Shape control; Signal and communications theory; Signal, noise; Studies; Synthesis; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transfer functions; Transmission and modulation (techniques and equipments); Optimal filter; Non linear filter; Transmission channel; Iterative method; Equalization; Algorithm; Phase distortion; Optimization; Optical fiber dispersion; Digital filter; optical filters; Optical filter; Simulation; Optical transmission; Compensation; Analytical method; finite-impulse response (FIR) digital filters; Finite impulse response filter; Optical delay lines; System synthesis; Optical dispersion compensation; Transfer function; High rate transmission
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2006.881477

A quasi-analytic synthesis algorithm is presented to determine the coefficients of nonrecursive optical delay line filters with approximately constant or linear dispersion. These filters can be used to compensate the dispersion and dispersion slope effects in high-speed optical transmission systems. The synthesis of the coefficients is based on a rigorous analysis of the impact of transfer function on the filter's dispersion behavior. The advantages of this algorithm are that filters of arbitrary order have similar dispersion shapes and that the dispersion values of the filters can be adjusted by controlling a single parameter instead of optimizing all the filter coefficients independently. The realized dispersion shapes are reproducible, and no iterative algorithms are needed for the calculation. The abilities of the synthesized filters are proven in system simulations at 40 Gb/s. Therefore, filters of different orders were investigated in the static case (i.e., with a fixed dispersion) and the dynamic case, where the dispersion of the filter is adapted to the requirements of the simulated optical transmission channel. In addition, the influences of the filter's free spectral range and of the utilized bandwidth inside a filter period were investigated. To the best of our knowledge, both the analytical synthesis approach and the investigation of the optimal filter configuration are presented for the first time