Single-mode lasing in InGaAs nanopillars on SOI (Conference Presentation)

Abstract

The integration of III-V optoelectronics on Si substrates is essential for next-generation high-speed communications. The major issue in the integration of III-V semiconductor on Si is the lattice mismatch between Si and the III-V semiconductor material at the interface. The strain induced by the lattice mismatch can be relaxed when a nanostructure, such as a nanopillar (NP), is grown on Si. In this work, we experimentally determine the lasing mode by optically pumping a single InGaAs nanopillar grown on Si on insulator (SOI). The lasing features of the InGaAs NP are characterized with different optical techniques. Power dependent photoluminescence (PL) at 7K is carried out to determine the lasing threshold by increasing the excitation power. The carrier dynamics below and above the threshold have been studied at 7K from time-resolved photoluminescence (TRPL) experiments at different excitation powers. We have measured a decrease in the carrier lifetimes with a rise in excitation power until the nanostructure starts lasing. The lifetime corresponding to the laser mode is on the order of the sensitivity of the streak camera (±1ps) indicating the extremely short laser lifetime. The InGaAs nanolaser shows a single longitudinal mode because of the small length dimensions (<1μm). The wavelength of the laser mode emission changes with each NP excited due to the slight differences in dimensions between NPs. In addition, the quality of the crystal grown has been studied with temperature-dependent PL. These results will contribute to further optimization of the InGaAs nanolaser for integration of III-V optoelectronics on Si substrates.