Effect of the external reflector position on thethreshold current in complex-coupled DFB laser diodes

Abstract
A new method of controlling the phase of a propagating wave coupled between the laser facets and the internal loss grating in a complex-coupled DFB laser diode is introduced. The overlap between the optical mode and the lossy region is deduced from the measured threshold current. The method permits a controlled change of the operating conditions and allows a systematic study of the influence of an absorber on the laser dynamics.