[1] Friedrich Schiller Univ, Inst Opt & Quantum Elect, Abbe Ctr Photon, D-07743 Jena, Germany
[2] Univ Calif Berkeley, Berkeley, CA 94720 USA
[3] Helmholtz Inst Jena, D-07743 Jena, Germany
[4] Leibniz Inst Photon Technol eV, D-07745 Jena, Germany
[5] Friedrich Schiller Univ, Otto Schott Inst Mat Res, Abbe Ctr Photon, D-07743 Jena, Germany