Single-mode whispering gallery lasing from metal-clad GaN nanopillars.
An ordered hexagonal closed-packed nanopillar array is fabricated on GaN. A metal coating is then applied to encapsulate the pillars for promoting optical confinement within the cylindrical cavity. Room-temperature lasing at 373 nm is observed under pulsed excitation, at a lasing threshold of 0.42 MW/cm2. With pillar diameters of around 980 nm, the number of modes overlapping the emission spectrum is reduced, giving rise to single-mode whispering gallery stimulated emission. Finite-difference time-domain simulations are carried out for the prediction of resonant frequencies and electric field patterns corresponding to the resonant modes.
Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China.
K H
KH
Li
Zetao
Z
Ma
H W
HW
Choi
D005708:Gallium / Q000737:chemistry*; D007834:Lasers; D008670:Metals / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry
D008670:Metals; D012822:Silicon Dioxide; D005708:Gallium; C027235:gallium nitrate