title: Super-resolution imaging of lateral distribution for the blue-light emission of an InGaN single-quantum-well structure utilizing the stimulated emission depletion effect.
abstract: We have observed a remarkable decrease in photoluminescence (PL) from a blue-light emitting InGaN single-quantum-well (SQW) structure under the radiation of a green laser due to the stimulated emission depletion (STED) phenomenon. By extending the observed STED effect, super-resolution imaging of the blue-light emission lateral distribution was demonstrated for the InGaN-SQW structure through co-irradiation using a doughnut-shaped green light beam and a Gaussian-shaped violet excitation light beam. We measured point-spread functions (PSFs) to evaluate the spatial resolution of the system by imaging a small emission area. A lateral PSF size of ~150 nm was confirmed, which was approximately 40% smaller than that without the STED beam. This demonstrates that the STED technique is applicable for PL imaging of semiconductor quantum structures. The present approach may make possible a new strategy for characterizing and investigating the spatial inhomogeneity of emission properties and carrier dynamics in InGaN-based quantum wells, as well as in other semiconductor materials exhibiting quantum confinement effects.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kozawa
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kusama
authors.forename: Shunichi
authors.initials: S
authors.lastname: Sato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yokoyama
mesh_terms: D003952:Diagnostic Imaging / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D008027:Light; D012666:Semiconductors