Fig. 1. Schematic of the nonlinear Yb-doped fiber amplified system. (a) Oscillator, (b) amplifier, and (c) compressor. WDM, wavelength division multiplexer; YDF, Yb-doped fiber; ISO, isolator; OC, output coupler; QWP, quarter-wave plate; HWP, half-wave plate; PBS, polarized beam splitter; BF, birefringence filter; DCYDF, double-cladding Yb-doped fiber; C1–C3, collimators; M, high reflection mirror.

Fig. 2. Output characteristics of the oscillator. (a) Spectral emission versus pump power. (b) RF spectrum (34–45 MHz). Inset: RF spectrum in the span of 2 GHz.

Fig. 3. Spectrum of the amplified pulse with respect to pump power.

Fig. 4. Output power of the amplifier as a function of pump power.

Fig. 5. Pulse duration of the NLPs as a function of separation of the grating pair (red line, pedestal; blue line, spike).

Fig. 6. (a) Shortest pulse duration of a compressed NLP at different pump powers (7.6–8.6 W). (b) Autocorrelation traces of an NLP at pump power of 8 W. Inset: the corresponding spike.

Fig. 7. Autocorrelation trace of the NLP at a pump power of 8 W before compression.

Fig. 8. Spectrum versus the pump power after compression. Inset: spectrum at pump power of 7–9 W.

Fig. 9. Output power with respect to pump power after compression.

Fig. 10. RF spectrum of the NLP from 34 to 45 MHz after compression. Inset: RF spectrum in the span of 2 GHz.