Interaction of Semiconductor Laser Chirp with Fiber Dispersion: Impact on WDM Directly Modulated System Performance

• Main Authors: Carmina Del Río Campos, Paloma R. Horche, Alfredo Martín Mínguez
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: DML
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.678.9083; http://www.thinkmind.org/download.php?articleid%3Dcenics_2011_1_40_60069

Abstract—In this paper, we have analyzed the interaction of semiconductor laser chirp with the fiber chromatic dispersion characteristics in order to study the impact on a Wavelength Division Multiplexing (WDM) directly modulated system performance. Also, we have demonstrated that the system transmission performance depends, strongly, on the Directly Modulated Laser (DML) output power and its adiabatic and transient chirp parameters. We have calculated by simulation, that the effect of DMLs chirp can be compensated by a negative dispersion fiber in a specific range of the DML output power. In addition, a pulse broadened by the positive dispersion fiber can be equalized using self-phase-modulation (SPM) in the optical fiber. The majority of metro and access networks are made up of conventional single-mode fibers (SMF) which are positive dispersion fibers. We have demonstrated that the optimum compensation is always feasible for such fibers by changing the optical output power in the DML laser. Furthermore, simulations suggest that this technique is able to enhance the performance of directly modulated wavelength division multiplexed systems if the power of each channel is chosen correctly. Keywords- directly modulated laser; adiabatic and transient chirp; linewidth enhancement factor; adiabatic coefficient; fiber chromatic dispersion. I.