[1] Aston Univ, Sch Engn & Appl Sci, Photon Res Grp, Birmingham B4 7ET, W Midlands, England
[2] Russian Acad Sci, Siberian Branch, Inst Computat Technol, Novosibirsk 630090, Russia
[3] TOPTICA Photon AG, D-82166 Graefelfing, Germany
[4] Tampere Univ Technol, Optoelect Res Ctr, FIN-33101 Tampere, Finland