Coupling of quantum-well emission to waveguide–plasmon polaritons in rolled-up microtubes

We study the coupling of GaAs quantum wells to waveguide–plasmon polaritons supported by a thin InAlGaAs-based slab waveguide and a Ag grating. The hybrid photon–plasmon modes are excited in a freestanding emitter–waveguide–plasmon structure realized by rolling-up strained InAlGaAs-based layers and nanopatterned Ag structures. By varying the grating’s bar width, we tune the plasmonic resonance of the system. We observe by means of spatially, spectrally, and temporally resolved photoluminescence measurements, a coupling of the quantum-well emission to the waveguide–plasmon system for a specific grating’s bar width. Supported by finite-element simulations, we can assign the coupling to the excitation of a waveguide–plasmon polariton.