Frequency upshift via flash ionization phenomena using semiconductor plasma A. Nishida, M. Nakata, T. Oba, T. Higashiguchi, N. Yugami, Y. Sentoku and R. Kodama EPJ Web of Conferences, 59 (2013) 19004 Published online: 15 November 2013 DOI: 10.1051/epjconf/20135919004