Second harmonic generation at 399 nm resonant on the   $^{1}S_{0}-^{1}P_{1}$ transition of ytterbium using a periodically poled   LiNbO$_{3}$ waveguide
  We demonstrate a compact and robust method for generating a 399-nm light resonant on the $^{1}S_{0}-^{1}P_{1}$ transition in ytterbium using a single-pass periodically poled LiNbO$_{3}$ waveguide for second harmonic generation (SHG). The obtained output power at 399 nm was 25 mW when a 798-nm fundamental power of 380 mW was coupled to the waveguide. We observed no degradation of the SHG power for 13 hours with a low power of 6 mW. The obtained SHG light has been used as a seed light for injection locking, which provides sufficient power for laser cooling ytterbium. 
Takumi Kobayashi, Daisuke Akamatsu, Yoshiki Nishida, Takehiko Tanabe,   Masami Yasuda, Feng-Lei Hong, and Kazumoto Hosaka
physics.atom-ph physics.optics