Rolled-up InGaAs/GaAs quantum dot micro- and nanotube lasers

Abstract

Recently, rolled-up semiconductor tubes, formed when a coherently strained semiconductor bilayer is selectively released from the host substrate, have emerged as a promising technique to realize high performance optical micro and nanocavity devices [1–6]. Combining the advantages of both top-down and bottom-up fabrication processes, this approach offers an exceptional flexibility for achieving semiconductor micro- and nanotube structures with an epitaxially smooth surface and well controlled diameters and wall thicknesses using a single photolithography step. However, lasing in such tube structures has hitherto not been demonstrated. In this context, we have performed a detailed investigation of the fabrication and characterization of rolled-up micro- and nanotubes, with the incorporation of self-organized InGaAs/GaAs quantum dots as the gain media. We have achieved, for the first time, lasing in rolled-up semiconductor tubes at room temperature. The devices are characterized an ultralow threshold power (~ 4 μW), an intrinsic lasing linewidth of ~ 0.2–0.3 nm, and a linear polarization with the electric field parallel to the tube surface.