Dane: JC: Attosecond lighthouse

Original Lighthouse proposal / theory
http://prl.aps.org/abstract/PRL/v108/i11/e113904

Lighthouse in plasma mirror HHG:
http://www.nature.com/nphoton/journal/v6/n12/full/nphoton.2012.284.html

Lighthouse in gases:
http://www.nature.com/nphoton/journal/vaop/ncurrent/full/nphoton.2013.170.html