Broad optical bandwidth InGaAs-InAlGaAs light-emitting diodes fabricated using a laser annealing process

The use of a laser-induced quantum-well intermixing technique in the InGaAs-InAlGaAs material system is presented. We report blue shifts of up to 240 nm in the 1.55-μm emission wavelength, generated by exposure to a Nd:YAG laser. Variations in the optical intensity across the irradiating beam were used to laterally grade the bandgap along a sample. We used this technique to fabricate broad optical bandwidth, light-emitting diodes. The devices showed an increase in the full width half maximum of the emission spectrum from 125 nm in undisordered devices to over 260 nm in intermixed material. The output spectrum was also observed to be flat-topped (within 5%) across a wavelength range of 140 nm.