Fig. 1. Schematic of experimental setup. HWP, half-wave plate; PBS, polarization beam splitter; DM, dichroic mirror; LPF, long-pass filter; L, lens; ISO, optical isolator.

Fig. 2. (a) Measured spectrum of the amplified signal light. The shaded part under the black dash-dotted line represents the spectrum of the CW seed, and the blue solid curve represents the amplified signal light. (b) The dependence of the signal power on the pump power.

Fig. 3. Measured spectra of the second-stage signal light and the measured pulse duration.

Fig. 4. The dependence of the output power and pulse duration of the second-stage signal light on (a) the idler power with the pump power fixed at 3.8 W and (b) the pump power with the idler power fixed at 380 mW.

Fig. 5. (a) Measured spectra in the range of 790–799 nm and (b) the average power and pulse duration of the second-stage signal light.

Fig. 6. (a) Setup of RIN measurement. (b) The power spectral density (PSD) and (c) the relative intensity noise (RIN) of the CW seeding signal (red), the APD noise (gray), the 1030 nm Yb-doped pump (blue), the 515 nm SHG (green), and the OPG seeding signal (orange).

Fig. 7. Long-term power stability of the signal power at 792 nm.

Fig. 8. M² measurement of the second-stage output signal light. The blue X are the horizontal beam radii and the red Y are the vertical beam radii.