Graduate School in Nonlinear Science

Sponsored by the Danish Research Academy

MIDIT                               OFD                           CATS
Modelling, Nonlinear Dynamics       Optics and Fluid Dynamics     Chaos and Turbulence Studies
and Irreversible Thermodynamics     Risø National Laboratory      Niels Bohr Institute and 
Technical University of Denmark     Building 128                  Department of Chemistry
Building 321                        P.O. Box 49                   University of Copenhagen 
DK-2800 Lyngby                      DK-4000 Roskilde              DK-2100 Copenhagen Ø
Denmark                             Denmark                       Denmark


by Prof. Mario F.S. Ferreira
Department of Physics
University of Aveiro
3800 Aveiro,

MIDIT-seminar 415

Friday August 28, 1998, 14.00 h
at MIDIT, IMM Building 305, room 027

Abstract: A theorectical model is presented to describe the tuning, frequency noise, and modulation characteristics of tunable DBR lasers with two active and two passive sections. Among other results, it is shown that a nearly flat red-shifted FM response over several gigahertz can be obtained by nonuniform current injection and modulation of the lower carrier density section in the active region. Increasing the tuning current through the passive sections enhances the FM response. However, a higher FM efficiency is generally accompaned by a larger spectral linewidth. Some design optimization criteria for this type of lasers are pointed out and discussed.