Trans-Spectral Orbital Angular Momentum Transfer via Four-Wave Mixing in Rb Vapor
Trans-Spectral Orbital Angular Momentum Transfer via Four-Wave Mixing in Rb Vapor
复制标题
DOI：
10.1103/physrevlett.108.243601
复制
发表时间：
2012-06-14
影响因子：
8.6
通讯作者：
Franke-Arnold, S.
中科院分区：
文献类型：
--
作者：
Walker, G.;Arnold, A. S.;Franke-Arnold, S.
我们报道了在铷 - 85蒸汽的四波混频过程中，相位结构，特别是轨道角动量从近红外泵浦光到蓝光的转移。由空间光调制器整形的两个波长分别为780纳米和776纳米的泵浦激光的强度和相位分布，影响了在后续相干级联过程中产生的420纳米光的相位和强度分布。特别地，我们观察到与轨道角动量相关的相位分布完全从泵浦光转移到了蓝光。用更复杂的光分布进行泵浦会导致蓝光中空间模式的激发，这在很大程度上取决于相位匹配，从而证明了模式转移的参量性质。这些结果对原子气体中相位信息的写入和存储具有重要意义。
We report the transfer of phase structure and, in particular, of orbital angular momentum from near-infrared pump light to blue light generated in a four-wave-mixing process in Rb-85 vapor. The intensity and phase profile of the two pump lasers at 780 and 776 nm, shaped by a spatial light modulator, influences the phase and intensity profile of light at 420 nm, which is generated in a subsequent coherent cascade. In particular, we observe that the phase profile associated with orbital angular momentum is transferred entirely from the pump light to the blue. Pumping with more complicated light profiles results in the excitation of spatial modes in the blue that depend strongly on phase matching, thus demonstrating the parametric nature of the mode transfer. These results have implications on the inscription and storage of phase information in atomic gases.