Tunable continuous-wave Yb: GdCOB laser with an electro-optic crystal

We present a diode-pumped tunable continuous wave (CW) Yb:Ca4GdO(BO3)3 (Yb:GdCOB) laser using an electro-optic crystal based on the 2 F 5/2−2 F 7/2 transition. The highest output power of 3.21 W was achieved at an emission wavelength of 1030 nm with a slope efficiency of 27.2% with respect to the absorbed pump power. Combined with polarization components Yb:GdCOB, the electro-optical crystal KH2PO4 (KDP) formed a Lyot filter in the cavity and compressed the available gain bandwidth. With an adjustable voltage applied to the KDP crystal, the laser wavelength could be tuned from 1024 to 1034 nm. To our knowledge, it is the first study that has realized the tuning in Yb:GdCOB laser.