We demonstrate a self-starting 700 MHz repetition rate Yb:fiber laser incorporated with a phase biased nonlinear amplifying loop mirror as an artificial saturable absorber. The laser delivers a maximum power of 150 mW and a pulse width of 215 fs at a pump power of 710 mW. The integration of relative intensity noise (RIN) between 10 Hz and 10 MHz results in a minimum integrated RIN of 0.015%. The phase noise of the fundamental repetition rate was also characterized at different net-cavity dispersion. Although the laser is made of nonpolarization maintaining fiber, the mode locking sustains over two weeks in open air, showing its environmental stability.

Compact, high repetition rate ( ∼ G H z level) femtosecond fiber lasers are attractive for high-precision, high-speed scientific and engineering fields. However, the noise of such a laser seems far higher than low repetition rate ones, which limits its application. Motivated by this challenge, we combined the solid state and the fiber laser into a novel and highly stable “solid-state fiber laser” operating at 840 MHz repetition rate. Benefitting from the robust architecture of “optical cubes,” the laser shows an ultralow timing jitter (130 as) in free-running operation. This is the first time the timing jitter of a high repetition rate fiber laser has been brought to the attosecond level, to the best of our knowledge. This breakthrough makes an impact on the concept that the high repetition rate is associated with high timing jitter in fiber lasers and opens the way for real-world applications of these lasers.

We demonstrate two low-noise 750 MHz ytterbium fiber frequency combs that are independently stabilized to a continuous-wave laser. A bulk electro-optic modulator and a single-stack piezo-electric transducer are employed as fast actuators for stabilizing the respective cavity length to heterodyne beat notes. Both combs exhibit in-loop fractional frequency instabilities of $\sim {10}^{-18}$ at 1 s. To the best of our knowledge, this is the first demonstration of tightly phase-locked ($<1\mathrm{rad}$ root mean square phase noise integrated from 0.1 Hz to 10 MHz) fiber frequency combs with 750 MHz fundamental repetition rate.

We demonstrate a femtosecond all-polarization-maintaining Nd fiber laser working at 920 nm mode locked by a biased non-linear loop mirror. The broadest spectral width of the pulse is 25.2 nm and the output power is 8 mW with 320 mW pump power. The measured pulse width is 109 fs with extra-cavity compression. The laser configuration of all-polarization-maintaining fiber can directly enhance the environmental stability of generated pulses. The seed pulses of the oscillator were amplified over 400 mW, which served as the light source for a two-photon microscope. To the best of our knowledge, this is the first demonstration of a 920 nm femtosecond Nd polarization-maintaining fiber laser based on a non-linear loop mirror.

We demonstrate 503MHz fundamental high repetition rate operation in a ring cavity passively mode-locked Yb:fiber laser incorporating a novel wavelength–division-multiplexing collimator and a piece of all-solid photonic bandgap fiber. The Yb doped fiber was directly fabricated as one fiber pigtail into the functional collimator, greatly shortening the cavity length and facilitating the splicing operation. A 5cm long photonic bandgap fiber with abnormal dispersion at the lasing wavelength (centered at 1030nm) decreases the net dispersion for shorter output pulses. The spectral bandwidth of the pulse was 34nm. The direct output pulse was measured to be 156fs and the dechirped pulse was about 76fs. With this innovative Yb:fiber pigtailed WDM collimator, the ring cavity laser has the potential to work at a repetition rate up to GHz.

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