Light emission and wave guiding of quantum dots in a tube

We present microphotoluminescence investigations of InAs quantum dots (QDs) integrated into self-rolling InGaAs∕GaAs strained layers. The emission signal from the QDs is redshifted due to strain relaxation and increased in intensity after the strained layers are released from the substrate and rolled up into tubes. We detect waveguided light at the tube ends, which originates from the QDs at the laser excitation spot. The possibility of integrating quantum emitters into the tube walls acting as waveguides represents a major step toward the realization of flexible high quality factor optical resonators based on rolled-up nano- and microtubes.