Polarons generated by laser pulses in doped LiNbO3
Polarons generated by laser pulses in doped LiNbO3
复制标题
掺杂 LiNbO3 中激光脉冲产生的极化子
DOI：
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
E. Krätzig
中科院分区：
文献类型：
--
作者：
P. Herth;D. Schaniel;T. Woike;T. Granzow;M. Imlau;E. Krätzig
The temporal behavior of polarons generated by pulsed illumination of $mathrm{Li}mathrm{Nb}{mathrm{O}}_{3}$ crystals doped with Fe, $mathrm{Fe}+mathrm{Ti}$, and Cu is examined by detecting the light-induced absorption ${ensuremath{alpha}}_{mathrm{li}}$ in a pump-probe experiment. The decay of the polarons is satisfactorily described by a stretched exponential function over a temporal range of six decades. This fact is attributed to the dependence of the polaron lifetime on the distance to the nearest deep traps or to the disorder in $mathrm{Li}mathrm{Nb}{mathrm{O}}_{3}$. The dependence of the amplitude and dynamics of the light-induced absorption on the pump intensity are explained within the framework of these models. The wavelength dependence of ${ensuremath{alpha}}_{mathrm{li}}$ displays a maximum at about $740phantom{
ule{0.3em}{0ex}}mathrm{nm}$, revealing the optical excitation of small bound $mathrm{Nb}_{mathrm{Li}}{}^{4+}$ polarons. Temperature-dependent measurements in the range $293char21{}473phantom{
ule{0.3em}{0ex}}mathrm{K}$ reveal an Arrhenius behavior with an activation energy of about ${E}_{A}=0.38phantom{
ule{0.3em}{0ex}}mathrm{eV}$.
The temporal behavior of polarons generated by pulsed illumination of $mathrm{Li}mathrm{Nb}{mathrm{O}}_{3}$ crystals doped with Fe, $mathrm{Fe}+mathrm{Ti}$, and Cu is examined by detecting the light-induced absorption ${ensuremath{alpha}}_{mathrm{li}}$ in a pump-probe experiment. The decay of the polarons is satisfactorily described by a stretched exponential function over a temporal range of six decades. This fact is attributed to the dependence of the polaron lifetime on the distance to the nearest deep traps or to the disorder in $mathrm{Li}mathrm{Nb}{mathrm{O}}_{3}$. The dependence of the amplitude and dynamics of the light-induced absorption on the pump intensity are explained within the framework of these models. The wavelength dependence of ${ensuremath{alpha}}_{mathrm{li}}$ displays a maximum at about $740phantom{
ule{0.3em}{0ex}}mathrm{nm}$, revealing the optical excitation of small bound $mathrm{Nb}_{mathrm{Li}}{}^{4+}$ polarons. Temperature-dependent measurements in the range $293char21{}473phantom{
ule{0.3em}{0ex}}mathrm{K}$ reveal an Arrhenius behavior with an activation energy of about ${E}_{A}=0.38phantom{
ule{0.3em}{0ex}}mathrm{eV}$.