A theoretical model of multielectrode DBR lasers

A theoretical model for twoand three-section tunable DBR lasers is presented. The static tuning properties are studied in terms of threshold current, linewidth, oscillation frequency, and output power. Regions of continuous tuning are presented for three-section DBR lasers. We discuss different routes for continuous tuning, when the injection currents to the passive sections are varied, and the limitations on the continuous tuning range are clarified. By proper control of these currents a tuning range of approximately 400 GHz is predicted at 1.55 pm wavelength, which is in good agreement with the experimental results published thus far.