Publication Date:
2016-03-24
Description:
We demonstrate scalable terahertz (THz) generation by focusing terawatt, two-color laser pulses in air with a cylindrical lens. This focusing geometry creates a two-dimensional air plasma sheet, which yields two diverging THz lobe profiles in the far field. This setup can avoid plasma-induced laser defocusing and subsequent THz saturation, previously observed with spherical lens focusing of high-power laser pulses. By expanding the plasma source into a two-dimensional sheet, cylindrical focusing can lead to scalable THz generation. This scheme provides an energy conversion efficiency of 7 × 10 −4 , ∼7 times better than spherical lens focusing. The diverging THz lobes are refocused with a combination of cylindrical and parabolic mirrors to produce strong THz fields (〉21 MV/cm) at the focal point.
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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