说明:We demonstrate three-dimensional tomographic imaging using a Fresnel lens with broadband terahertz pulses. Objects at various locations along the beam propagation path are uniquely imaged on the same imaging plane using a Fresnel lens with different <weixin_38746918> 上传 | 大小:484kb
说明:In this work we present experiments by focusing 42 femtosecond laser pulses in air using three different focal length lenses: f=100, 30 and 5 cm. For the longest focal length, only the filament, which is a weak plasma column, is observed. When the sh <weixin_38688855> 上传 | 大小:678kb