Operation of multiphonon-assisted laser in the nanosecond time scales

. Electron – phonon coupling can tailor electronic transition processes and result in direct lasing far beyond the fluorescence spectrum. The applicable time scales of these kinds of multiphonon-assisted lasers determine their scientific boundaries and further developments, since the response speed of lattice vibrations is much slower than that of electrons. At present, the temporal dynamic behavior of multiphonon-assisted lasers has not yet been explored. Herein, we investigate the Q-switched laser performance of ytterbium-doped YCa 4 O ð BO 3 Þ 3 (Yb:YCOB) crystal with phonon-assisted emission in nanosecond scales. Using different Q-switchers, the three-phonon-assisted lasers around 1130 nm were realized, and a stable Q-switching was realized in the time domain from submicroseconds to tens of nanoseconds. To the best of our knowledge, this is the longest laser wavelength in all pulse Yb lasers. The minimum pulse width and maximum pulse energy are 29 ns and 204 μ J, respectively. These results identify that the electron – phonon coupling is a fast physical process, at least much faster than the present nanosecond pulse width, which supports the operation of multiphonon-assisted lasers in the nanosecond range. In addition, we also provide a simple setup to create pulse lasers at those wavelengths with weak spontaneous emission.