Fig. 1. Schematic of the NCPA system. BPF, bandpass filter; WDM, wavelength division multiplex; SM-LD, single-mode laser diode; YDF, Yb-doped gain fiber; PDG, pulse delay generator; AOM, acoustic optical modulator; PDOI, polarization dependent optical isolator; MM-LD, multi-mode laser diode; DM, dichromic mirror; TG, transmission grating; HR, high reflecting mirror; PCF, photonic crystal fiber.

Fig. 2. (a) RF spectrum of the oscillator. (b) The AC trace of the laser pulses from the oscillator.

Fig. 3. Comparison of the transmission spectra after the BPF and the oscillator.

Fig. 4. (a) Spectral distribution from amplified pulses on linear and logarithmic (inset) scale; (b) AC trace of compressed pulses.

Fig. 5. (a) Dependence of output power versus the pump power for the main amplifier; (b) measured power stability and pulse train; (c) M² value of this NCPA system.

Fig. 6. AC traces at different pulse energies (a)–(c) with BPF and (d)–(f) without BPF.