Abstract

We have demonstrated frequency selectivity and single-longitudinal-mode operation in a multisection gain-guided laterally-coupled-cavity (LC2) semiconductor laser. The device consists of two strongly coupled stripe lasers, each having two electrodes. The longer (~400 mm) served as a gain-section electrode and was forward biased, and the shorter (50100 mm) was reverse-biased and therefore provided an absorbing section. The absorbing-section electrodes of the two lateral elements were located at opposite ends of the device. By choosing the length and adjusting the reverse voltage of these sections, we could vary the magnitude and the phase of the reflectivity at each end. A detailed round-trip analysis showed that such a device should exhibit a periodic frequency dependence of the mode threshold gain. The fine details of this periodic behavior depended on the operating conditions and could be controlled. In the experiment isolated equispaced longitudinal-mode-operation was demonstrated. The frequency of these modes could be tuned by varying the absorbing section voltages. The operating conditions could be easily set for a single-longitudinal-mode operation.

© 1990 Optical Society of America