Semiconductor Lasers Operating Continuously in the ``Visible'' at Room Temperature

Continuous operation of AlxGa1−xAs–Aly Ga1−yAs–AlzGa1−zAs double heterostructure injection lasers at room temperature has been achieved with diodes whose lasing energy was as high as 1.61 eV (7730 Å). This energy was achieved with y = 0.20, and at this energy the far-field radiation pattern was visible. In the pulsed mode, low thresholds have been achieved up to 7450 Å (1.66 eV) using both broad-contact and stripe-geometry lasers. The lasing threshold remains relatively unchanged in the range y = 0 to 0.21.