Optimum design conditions for AlGaAs window stripe lasers

The maximum available CW optical power from the AlGaAs window stripe laser was investigated both theoretically and experimentally. It is found that a thin third AlGaAs layer thickness and high-quality pulsed lasing characteristics, such as low threshold current density and high external differential quantum efficiency, which are obtained from refractive index guiding and short window-region length, are necessary to increase CW optical power. Stable fundamental lateral transverse mode CW operation was achieved at 55 mW (∼4.7 MW/cm2) in a window stripe (WS) laser with 3 μm stripewidth, which is about five times higher than the typical catastrophic optical damage (COD) threshold in conventional structure lasers. It was also found that a high-quality window stripe laser with 3 μm stripewidth operated at 30 mW (∼2.6 MW/cm2) for more than 3500 h.