title: Coupled nanowire-based hybrid plasmonic nanocavities on thin substrates.
abstract: We theoretically analyze nanowire-based hybrid plasmonic nanocavities on thin substrates at visible wavelengths. In the presence of thin suspended substrates, the hybrid plasmonic modes, formed by the coupling between a metal nanowire and a dielectric nanowire with optical gain, exhibit negligible substrate-mediated characteristics and overlap better with the gain region. Consequently, the confinement factor of the guided hybrid modes is enhanced by more than 42%. However, the presence of significant mirror loss remains the main challenge to lasing. By adding silver coatings with a sufficient thickness range on the two end facets, we show that the reflectivity is substantially enhanced to above 50%. For a coating thickness of 50 nm and cavity length of about 4 μm, the quality factor is above 100.
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, 11529 Taipei, Taiwan ; Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan.
authors.forename: Pi-Ju
authors.initials: PJ
authors.lastname: Cheng
authors.affiliation: Institute of Optoelectronic Sciences, National Taiwan Ocean University, 20224 Keelung, Taiwan.
authors.forename: Chih-Kai
authors.initials: CK
authors.lastname: Chiang
authors.affiliation: Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, 20224 Keelung, Taiwan.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chung
authors.affiliation: Department of Photonics, National Chiao Tung University, 30010 Hsinchu, Taiwan.
authors.forename: Chung-Hao
authors.initials: CH
authors.lastname: Tien
authors.affiliation: Institute of Optoelectronic Sciences, National Taiwan Ocean University, 20224 Keelung, Taiwan ; Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, 20224 Keelung, Taiwan.
authors.forename: Tzy-Rong
authors.initials: TR
authors.lastname: Lin
keywords: Laser reonators; Nanomembrane; Nanowires; Semiconductor lasers; Surface plasmons; Waveguides