Fig. 1. Schematic diagram of the experimental setup. DM, dichroic mirror; GTI1, GTI2, Gires–Tournois interferometer mirrors; LD, fiber-coupled laser diode; M1–M3, concave mirrors; M4, plane mirror; OC, output coupler; SESAM, semiconductor saturable absorber mirror.

Fig. 2. With a 10% transmittance of OC, average output power versus pump power for the Yb:CALGO laser at 1041 nm.

Fig. 3. The output power stability of the Yb:CALGO oscillator in 3 h.

Fig. 4. The output laser spectrum of Yb:CALGO femtosecond oscillator.

Fig. 5. Autocorrelation trace of center wavelength of 1041 nm.

Fig. 6. The typical pulse train of mode-locking in different timescales: (a) 2 ns, (b) 10 ns, and (c) 2 s.

Fig. 7. Typical RF spectrum of the Yb:CALGO laser with the RBW of 1 kHz. Inset: RF spectrum at 1 GHz wide-span with the RBW of 300 kHz.

Fig. 8. The beam spatial profile of the Yb:CALGO laser at the output power of 10 W.