Open AccessPlasmonically enhanced random lasing and weak localization of light in powdered Nd3+ doped lithium niobate and its spectral transformation
Author(s) -
Xinyan Ma,
Jingwen Zhang,
Yingce Wang,
Jianxiang Lang,
Hua Zhao
Publication year - 2019
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.27.028551
Subject(s) - materials science , lasing threshold , optics , scattering , lithium niobate , photoluminescence , wavelength , optoelectronics , physics
We report surface plasmon enhanced random lasing action and weak localization owing to charge accumulation on the grain boundaries and its spectral transformation in powdered Nd 3+ doped lithium niobate (Nd: LN) specimens. Accumulative charge density resulting from screening of electric field of spontaneous polarization was estimated, proving that surface plasmons (SPs) can be excited on the grain boundaries of powdered Nd: LN. The SP based scattering is believed responsible for random lasing to occur, which was further confirmed by the estimation of the scattering mean free path and the scattering cross section and intriguing three step-like backscattering reduction observed in the process of monitoring the variation of reflection spectrum with increasing pumping power. Under a certain pumping power, the powdered Nd: LN specimen was melted locally and this resulted in great changes in random lasing wavelengths. To delve into the reason behind these changes, photoluminescence spectra of the specimens were measured before and after melting. By taking a close look at their dynamics and slopes, it was found that spectral transformation of random lasing occurred owing to the change of lattice structure in powdered Nd: LN.