Modeling self-pulsating DFB lasers with an integrated phase tuning section

A theoretical model of a self-pulsating three-section DFB laser with an int egrated phase tuning section is established. It is based on traveling wave equations and the standard carrier rate equations. Parameters of an existin g device are used for applying the model. Key conditions and characteristic s of self-pulsations (SPs) are modeled and compared with experimental resul ts. The important role of phase tuning for turning on the SP is pointed out . The dependence of the SP regime on the detuning between the Bragg wavelen gths in the laser and reflector is determined and the essential role of pha se-readjustement is identified. Frequency tuning via the laser currents, as well as the pulse shape at various frequencies, is investigated. This allo ws us to identify the mechanism for frequency tuning. The model turns out t o be a good tool to improve our knowledge of the self-pulsation effect and to design optimized devices.