Modulated-cap thin p-clad antiguided array lasers

Antiguided array lasers were fabricated in thin p-clad, InGaAs/GaAs single quantum well material. The required lateral refractive index variation was achieved by precisely modulating the thickness of the GaAs cap layer using a novel pulsed anodization/etching technique. Edge emitting arrays have 5 lasers on 9.5 micrometer centers with 6 micrometer wide gain regions and arrays having 20 lasers on 7 micrometer centers with 5 micrometer wide gain regions were characterized. At 1.2 times the pulsed current threshold (I th ), the central lobe of the lateral far field of the 5 element arrays contained about 55% of the beam power and were nearly diffraction limited (FWHM equals 1.3 degrees). At 1.2 I th , the central lobe of the 20 element arrays contained about 75% of the beam power and were about twice the diffraction limit (FWHM) equals 0.8 degrees). At 10 I th , the central lobe of the 20 element arrays contained about 60% of the beam power and were about 1.6 degrees wide.