Blue and Green Low Threshold Laser Diodes With InAlN Claddings

We report on
$300~\mu \text{m}$
short cavity single transverse mode LDs employing
$n$
-type InAlN cladding layers. Threshold currents in the blue and green spectral range of 3.3 and 12.0 mA are demonstrated, respectively. This is accompanied by low electrical power consumption for optical powers in the mW range. Compared to conventional AlGaN-based devices having nominally identical active regions, an increase in modal gain is demonstrated, responsible for a ≈25% reduction in threshold currents. Fast-axis far field divergence angle measurements indicate that the modal gain improvement can be ascribed to a higher optical confinement factor when using InAlN.