  This work reports single-frequency laser oscillation at 1003.4 nm of an
optically pumped external cavity semiconductor laser. By using a gain structure
bonded onto a high conductivity substrate, we demonstrate both theoretically
and experimentally the strong reduction of the thermal resistance of the active
semiconductor medium, resulting in a high power laser emission. The
spectro-temporal dynamics of the laser is also explained. Furthermore, an
intracavity frequency-doubling crystal was used to obtain a stable single-mode
generation of blue (501.5 nm) with an output power around 60 mW.
