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.