Distributed feedback semiconductor laser with segmented electrode - has successive sections with optical feedback network giving several phase shifts, successive current injectors and modulator

摘要

The laser is divided into sections (S1,S2) across which extends a light guide with the optical feedback network (20) to give two successive phase shifts (22,24) chosen to regulate the light intensity along the active stripe (10). A succession of d.c. sources (C1,C2) create successive current densities, injecting carriers into those sections to amplify the light whose frequency is selected by feedback. A current modulator (CM) creates a current density of a.c. modulation along with a d.c. bias modulation current (I1) in the modulation section (S1) to modulate the selected frequency. The d.c. current density injected in this section is weaker than in the other section (S2). USE/ADVANTAGE - Telecommunication by optical fibre. Controls simultaneously the emitted frequency and a narrow line width spectrum.