title: Single-Mode Lasing from "Giant" CdSe/CdS Core-Shell Quantum Dots in Distributed Feedback Structures.
abstract: "Giant" semiconductor quantum dots (GQDs) have tremendous potential for applications in laser devices. Here, CdSe/CdS core-shell GQDs (11 monolayers) have been synthesized as lasing gain material. The photoluminescence decay of the GQD ensemble is single-exponential, and the two-photon absorption cross-section is above 105GM. This article presents a versatile method for fabrication of CdSe/CdS GQD distributed feedback (DFB) lasers by laser interference ablation. A high-quality surface-relief grating structure can be readily created on the GQD thin films, and the relationship between laser beam intensity and surface modulation depth is studied. With appropriate periods, single-mode lasing emission has been detected from these devices under excitation wavelengths of 400 and 800 nm. The laser thresholds are as low as 0.028 and 1.03 mJ cm-2, with the lasing Q-factors of 709 and 586, respectively. Lasing operation is realized from the direct laser interference-ablated QD DFB structures for the first time.
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Liao
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
authors.forename: Bihu
authors.initials: B
authors.lastname: Lv
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China.
authors.forename: Min
authors.initials: M
authors.lastname: Xiao
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Xu
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Yufen
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Changgui
authors.initials: C
authors.lastname: Lu
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Advanced Photonics Center, School of Electronic Science & Engineering, Southeast University , Nanjing 210096, China.
authors.forename: Jiayu
authors.identifier: http://orcid.org/0000-0001-7868-6346
authors.initials: J
authors.lastname: Zhang
keywords: distributed feedback lasers; giant quantum dots; laser interference ablation; optical gain; surface-relief grating