Spatiotemporal coherent control of lattice vibrational waves.
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.
Feurer
T
T
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Vaughan
Joshua C
JC
Nelson
Keith A
KA