title: Threshold reduction in a cyclic photonic molecule laser composed of identical microdisks with whispering-gallery modes.
abstract: Lasing modes in cyclic photonic molecules (CPMs) composed of several identical thin semiconductor microdisks in free space are studied in a linear approximation. Maxwell's equations with exact boundary conditions and the radiation condition at infinity are considered as a specific eigenvalue problem that enables one to find natural frequencies and threshold gains. It is demonstrated that careful tuning of the distance between the disks in CPMs is able to drastically reduce the lasing thresholds of the whispering-gallery modes having small azimuth indices.
authors.affiliation: Institute of Radio-Physics and Electronics NASU, Kharkov 61085, Ukraine. elena_smotrova@yahoo.com
authors.forename: Elena I
authors.initials: EI
authors.lastname: Smotrova
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Nosich
authors.forename: Trevor M
authors.initials: TM
authors.lastname: Benson
authors.forename: Phillip
authors.initials: P
authors.lastname: Sewell