[1] Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada
[2] Electrotech Lab, Tsukuba, Ibaraki 305, Japan
[3] Moscow MV Lomonosov State Univ, Ctr Int Laser, Moscow, Russia
[4] Univ Quebec, Dept Chim, Montreal, PQ H3C 3P8, Canada
[5] Univ Sherbrooke, Fac Sci, Dept Phys, Sherbrooke, PQ J1K 2R1, Canada