Third harmonic order imaging as a focal spot diagnostic for high intensity laser-solid interactions

Journal article

As the state of the art for high power laser systems increases from terawatt to petawatt level and beyond, a crucial parameter for routinely monitoring high intensity performance is laser spot size on a solid target during an intense interaction in the tight focus regime (<10m). Here we present a novel, simple technique for characterizing the spatial profile of such a laser focal spot by imaging the interaction region in third harmonic order (3laser). Nearly linear intensity dependence of 3laser generation for interactions >1019Wcm2 is demonstrated experimentally and shown to provide the basis for an effective focus diagnostic. Importantly, this technique is also shown to allow in-situ diagnosis of focal spot quality achieved after reflection from a double plasma mirror setup for very intense high contrast interactions (>1020Wcm2) an important application for the field of high laser contrast interaction science. © Cambridge University Press 2009.

Authors: Dromey, B; Bellei, C; Carroll, D; Clarke, R; Green, J

• Publication status: Published
• Journal: Laser and Particle Beams
• Volume: 27
• Issue: 2
• Pages: 243-248
• Publication date: 2009-06-01
• DOI: 10.1017/S0263034609000329
• EISSN: 1469-803X
• ISSN: 0263-0346