Monochromatic imaging and angular distribution measurements of extreme ultraviolet light from laser-produced Sn and SnO2 plasmas

Abstract

Properties of extreme ultraviolet (EUV) emission from laser-produced Sn and SnO2 plasmas were investigated. EUV emission images were taken with a monochromatic imager for 13.5nm with 4% bandwidth. It was found that the EUV emitting plasma is not formed symmetrically with respect to the target surface normal but extends toward laser incident axis. This result is consistent with the angular distribution of EUV emission peaked toward the direction nearly perpendicular to the laser axis. The asymmetric plasma can be attributed to the interaction of a long laser pulse with expanding plasma along the path of laser incidence.