Feurer T, Vaughan Joshua C, Nelson Keith A
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Science. 2003 Jan 17;299(5605):374-7. doi: 10.1126/science.1078726.
We achieved automated optical control over coherent lattice responses that were both time- and position-dependent across macroscopic length scales. In our experiments, spatiotemporal femtosecond pulse shaping was used to generate excitation light fields that were directed toward distinct regions of crystalline samples, producing terahertz-frequency lattice vibrational waves that emanated outward from their multiple origins at lightlike speeds. Interferences among the waves resulted in fully specified far-field responses, including tilted, focusing, or amplified wavefronts. Generation and coherent amplification of terahertz traveling waves and terahertz phased-array generation also were demonstrated.
我们实现了对相干晶格响应的自动化光学控制，该响应在宏观长度尺度上既与时间相关又与位置相关。在我们的实验中，时空飞秒脉冲整形被用于产生指向晶体样品不同区域的激发光场，从而产生太赫兹频率的晶格振动波，这些波以类光速度从其多个源向外传播。波之间的干涉导致了完全特定的远场响应，包括倾斜、聚焦或放大的波前。还展示了太赫兹行波的产生和相干放大以及太赫兹相控阵的产生。
