Fig. 1. Schematic of the integrated all-fiber Yb:fiber laser frequency comb system. WDM, wavelength division multiplexer; PZT, piezoelectric ceramic transducer; DM, dichroic mirror; PCF, photonic crystal fiber; PPLN, periodically poled lithium niobate; APD, avalanche photodiode.

Fig. 2. (a) Residual fluctuations of the repetition frequency; (b) the Allan deviation calculated by data shown in (a); (c) the spectra of the oscillator (red line) and after the amplifier (black line).

Fig. 3. (a) End face of NKT HC 1060 fiber by SEM from NKT photonics; (b) end face of HN-PCF by SEM; (c) fiber HI 1060 acts as bridge fiber to connect the two PCFs together with loss less than 3 dB; (d) measured autocorrelation trace of the pulses compressed by HC PCF.

Fig. 4. (a) The experiment (black line) octave-spanning spectrum generated from HN-PCF; (b) the fceo signal detected from the APD at the resolution bandwidth of 300 kHz.