Dispersion effects in four-wave mixing measurements of ions in solids.
Dispersion effects in four-wave mixing measurements of ions in solids.
复制标题
固体中离子的四波混合测量中的色散效应。
作者：
R. Powell;Stephen A. Payne
我们对 BeAl(2)O(4)、Gd(3)Sc(2)Ga(3)O(12) 和 LaMgAl(11)O(19) 三种晶体中的 Cr(3+) 离子进行了非简并四波混频测量。两束相同频率的激光束用于共振泵浦Cr(3+)的吸收带之一，并且具有442至1064 nm的三种不同波长的探测光束用于从激光诱导布居光栅产生信号。发现观察到的四波混合信号强度随着探测光束的波长减小而增加。利用模型根据 Cr(3+) 离子处于亚稳态与基态时极化率的变化来解释这些结果，结果发现色散效应可以通过单振荡器模型来描述，其中 Cr(3+) 的最低能量电荷转移跃迁对信号做出了主要贡献。
We have performed nondegenerate four-wave mixing measurements on Cr(3+) ions in three crystals: BeAl(2)O(4), Gd(3)Sc(2)Ga(3)O(12), and LaMgAl(11)O(19). Two laser beams of the same frequency were used to resonantly pump one of the absorption bands of Cr(3+), and probe beams with three different wavelengths ranging from 442 to 1064 nm were used to generate a signal from the laser-induced population grating. The observed four-wave mixing signal strength was found to increase as the wavelength of the probe beam was decreased. A model was utilized to explain these results based on the change in polarizability of the Cr(3+) ions when they are in the metastable state versus the ground state, and it was found that the dispersion effects can be described by a single-oscillator model with the lowest-energy charge-transfer transition of Cr(3+) making the dominant contribution to the signal.