Continuous and pulsed room temperature lasing behaviour at 1.55 μn on high quality factor photonic crystal microcavities

In this work we show room temperature lasing at 1.5 μm in photonic crystal microcavities in air bridge membranes with a single layer of self-assembled quantum wires (QWRs). Low threshold values around 10 μW have been measured, along high quality factors Q ~ 55000 using L7-type photonic crystal microcavities. Solid-source molecular beam epitaxy has been used for the synthesis of the InP/InAs epitaxial material comprising a single layer of InAs QWRs. The main axis of the cavity is always parallel to the QWRs, which grow along the direction. No lasing has been obtained for L7 cavities with axis parallel to the (i.e., perpendicular to the direction of the QWRs), showing the strong one-dimensional character of the QWRs inside the photonic cavity. Under pulsed excitation the lasing spectra show asymmetric lineshapes and an evolution related with thermal and absorption saturation effects.