title: Lithographically Defined, Room Temperature Low Threshold Subwavelength Red-Emitting Hybrid Plasmonic Lasers.
abstract: Hybrid plasmonic lasers provide deep subwavelength optical confinement, strongly enhanced light-matter interaction and together with nanoscale footprint promise new applications in optical communication, biosensing, and photolithography. The subwavelength hybrid plasmonic lasers reported so far often use bottom-up grown nanowires, nanorods, and nanosquares, making it difficult to integrate these devices into industry-relevant high density plasmonic circuits. Here, we report the first experimental demonstration of AlGaInP based, red-emitting hybrid plasmonic lasers at room temperature using lithography based fabrication processes. Resonant cavities with deep subwavelength 2D and 3D mode confinement of λ2/56 and λ3/199, respectively, are demonstrated. A range of cavity geometries (waveguides, rings, squares, and disks) show very low lasing thresholds of 0.6-1.8 mJ/cm2with wide gain bandwidth (610 nm-685 nm), which are attributed to the heterogeneous geometry of the gain material, the optimized etching technique, and the strong overlap of the gain material with the plasmonic modes. Most importantly, we establish the connection between mode confinements and enhanced absorption and stimulated emission, which plays critical roles in maintaining low lasing thresholds at extremely small hybrid plasmonic cavities. Our results pave the way for the further integration of dense arrays of hybrid plasmonic lasers with optical and electronic technology platforms.
authors.affiliation: Department of Physics and Bernal Institute, University of Limerick , Limerick, Ireland.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Gocalinska
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Justice
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Farzan
authors.initials: F
authors.lastname: Gity
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Ian
authors.initials: I
authors.lastname: Povey
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Brendan
authors.initials: B
authors.lastname: McCarthy
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Martyn
authors.initials: M
authors.lastname: Pemble
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pelucchi
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Wei
authors.affiliation: Department of Physics and Bernal Institute, University of Limerick , Limerick, Ireland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Silien
authors.affiliation: School of Physics and Technology, and Institute for Advanced Studies and Center for Nanoscience and Nanotechnology, Wuhan University , Wuhan 430072, China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Xu
authors.affiliation: Tyndall National Institute, University College Cork , Cork, Ireland.
authors.forename: Brian
authors.initials: B
authors.lastname: Corbett
keywords: AlGaInP heterostructures; Plasmonic lasers; Purcell effect; enhanced stimulated emission; top-down lithography