Resonance amplification of defect emission in ZnO-inverted opal.
Transformation of broadband emission of oxygen defects in the carcass of ZnO-inverted opal into a multiple-mode amplified spontaneous emission band has been observed in the spectral interval of a photonic bandgap upon increasing excitation intensity. The mode structure has been assigned to amplification of emission coupled to resonance modes of the self-selected distributed Bragg resonator. The surprisingly low 2 W/cm(2) onset of amplification has been explained by the long radiative decay time of defect states populated according to the three-level excitation scheme. The decrease of emission intensity between amplified peaks has been associated with the saturation of the ZnO defect emission.
Khunsin
Worawut
W
Tyndall National Institute, University College Cork, Lee Maltings, Cork, Ireland.
Scharrer
Michael
M
Aagesen
Larry K
LK
Anderson
Mark A
MA
Chang
Robert P H
RP
Sotomayor Torres
Clivia M
CM
Romanov
Sergei G
SG