Highly reliable and mode-stabilized (GaAl)As double-heterostructure visible lasers on p-GaAs substrate

A new channeled-substrate (GaAl)As double-heterostructure (DH) visible laser on p-GaAs, called a V-channeled Substrate Inner Stripe (VSIS) laser, has been developed. A built-in optical waveguide and internal current confinement are realized in the structure. The lasers with emission wavelength of 760-790 nm reproducibly provide a single mode operation up to 20 mW/facet cw. For (GaAl)As visible lasers, Te is usually used as a dopant in the n-type cladding layer. This Te, however, is found to lower the reliability of the conventional oxide-stripe lasers where the active layer is deposited on the Te doped n-type cladding layer, even when the Te concentration is lower than 5 × 10¹⁷cm^-3. On the other hand, the n-type cladding layer is grown on the active layer in the VSIS laser. Consequently, the degradation which arises from the rather poor quality of the Te doped cladding layer is suppressed in the VSIS laser although the Te concentration is as high as 1 × 10¹⁸cm^-3. The VSIS lasers with nm have been continuously operating with almost no degradation for 2000 hours at 10 mW/ facet (5 mW/µ m) operation at 50 °C up to the present.