Saturation of the junction voltage in stripe-geometry (AlGa)As double-heterostructure junction lasers

Abstract

Saturation of the junction voltage has been observed to occur at the onset of lasing in cw stripe-geometry (AlGa)As double-heterostructure junction lasers. Simultaneous measurements of the nonlasing but amplified spontaneous emission confirm that saturation of the optical gain and spontaneous emission accompany the voltage saturation as expected. With well-behaved lasers the observed saturation is maintained over currents to at least 50% above threshold. In other devices, a loss of saturation is commonly observed to occur simultaneously with a nonlinearity in the current dependence of the lasing emission.