Double-clad fiber amplifier for broadband tunable ytterbium-doped oxyorthosilicates lasers

Broadband tunable continuous-wave laser action and double-clad fiber amplifier of Yb:GSO, Yb:GYSO and Yb:LYSO crystals have been demonstrated. Under 940 nm diode pump, the free-running Yb:GSO, Yb:GYSO and Yb:LYSO lasers output power are 3.1 W at 1091 nm, 3.0 W at 1083 nm and 1.1 W at 1058 nm, with the corresponding optical-to-optical conversion efficiency of 57%, 42% and 13%, respectively. By using intra-cavity dispersion prism and a slit to restrict the spatial mode structure, continuously tunable range extends from 1002 to 1120 nm, covering some specific wavelengths as required for metrological or optical pumping applications. By using an ytterbium-doped double-clad fiber amplifier, several watts were obtained at tunable wavelengths. Particularly, the output power was 6.5 W for Yb:GSO, 12 W for Yb:GYSO, and 4 W for Yb:LYSO at 1083 nm, which matched the atomic transition wavelength useful for optical pumping of helium.