Achieving selectivity and reduced absorption for low loss monolithic InAs QD based III-V photonic integration

Abstract A straightforward method to achieve monolithic selective area intermixing in an epitaxially grown InAs quantum dot (QD) based laser structure is demonstrated, enabling the development of O-band monolithic photonic integrated circuits. Blue shifts of up to 37 nm are demonstrated in electrically biased laser diode wavelength and photoluminescence measurements. Significantly reduced absorption by up to 38 cm−1, measured by the segmented contact technique, in the wavelength range of 1220 nm – 1320 nm is achieved for selectively intermixed compared to unintermixed samples. For achieving the selectivity and reduced absorption, hydrogen proton bombardment with a 7° angle and doses of 5 × 1012 cm−2 and 5 × 1013 cm−2 and 300 keV energy is used to create defect sites within the InAs QD based active region followed by rapid thermal annealing with a ∼200 nm SiO2 capping layer as a simple means to tune the bandgap. This work establishes the viability of selective area band-gap-tuning in InAs QD laser epitaxy for low loss monolithic III–V photonic integration.