Open AccessPumping-power-dependent photoluminescence angular distribution from an opal photonic crystal composed of monodisperse Eu^3+/SiO_2 core/shell nanospheres
Author(s) -
Le Dac Tuyen,
Jian Hung Lin,
Cheng Yi Wu,
Po-Tse Tai,
Jau Tang,
Le Quoc Minh,
Hung-Chih Kan,
Chia Chen Hsu
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.015418
Subject(s) - photoluminescence , materials science , photonic crystal , photonics , optoelectronics , optics , green light , monochromatic color , core (optical fiber) , population inversion , emission spectrum , emission intensity , spectral line , laser , physics , blue light , astronomy , composite material
High quality opal photonic crystals (PhCs) were successfully fabricated by self-assembling of monodisperse Eu(3+)/SiO(2) core/shell nanospheres. Angular resolved photoluminescence (PL) spectra of a PhC sample were measured with different pumping powers, and its PL emission strongly depended on spectroscopic position of the photonic stop band and the optical pumping power. Suppression of the PL occurred in the directions where the emission lines aligned with the center of the photonic stop band. Suppression and enhancement of the PL were observed at low- and high-pumping powers, respectively, in the directions where the emission lines were located at the edges of the photonic stop band. When pumping power exceeded 6 µJ/pulse, a super-linear dependence was found between the pumping power and PL intensity. The dramatic enhancement of PL was attributed to the amplification of spontaneous emission resulted from the creation of large population inversion and the slow group velocity of the emitted light inside the PhC. The opal PhC provided highly angular-selective quasi-monochromatic PL output, which can be useful for a variety of optical applications.