Data are presented on the simplest form of multiple‐stripe laser array, a gain‐guided two‐stripe configuration of wide spacing (∼15 mgr;m, weak or moderate coupling), showing the effects of the two forms of supermode oscillation on the laser’sL‐Icharacteristic, far‐field emission pattern, and radiation spectrum. Measurements of the spatial dependence of the gain, at various currents, for a modified (antireflection‐coated) two‐stripe AlxGa1−xAs‐GaAs quantum‐well heterostucture laser diode provides a basis for explaining the onset of oscillations of both forms of supermodes (n=1, symmetric or ‘‘even,’’ andn=2, antisymmetric or ‘‘odd’’). These results agree with the significant band filling of the single quantum well and the supermode energy splitting of ∼15 meV in high‐level laser operation. The data and results presented are obtained by operating antireflection‐coated diodes in a tunable external grating cavity and by taking gain measurements on and between the stripes at the Fabry–Perot facets.
展开▼
