Femtosecond filamentation induced fluorescence technique for atmospheric sensing*
Yuan Shuaia),b),c), Chin See Leangc), Zeng He-Pinga),b),†
Fig.#cod#x00A0;1. Typical spectra in the ranges of 355#cod#x2013;361#cod#x00A0;nm a and 384#cod#x2013;390#cod#x00A0;nm b for filament-induced fluorescence of CN in air. The filament was generated by focusing a 400-nm pulse of 47#cod#x00A0;fs 1.8#cod#x00A0;mJ with a lens of 30-cm focal length. The filament region was under a continuous stream of CO 2 . The fluorescence was detected from the side at room temperature 20#cod#x00A0;#cod#x00B0;C.