Long-term carrier-envelope-phase stabilized fiber-bulk hybrid laser with millihertz linewidth and 50 W average power

Phase noise suppression for a high-power optical frequency comb

“…The FWHM of the f 0 signal was measured as 52 kHz via a Lorentz fit, which was comparable to the high-power Yb-fiber frequency comb reported in [19]. In comparison with other results reported in [20][21][22][23][24][25], the linewidth was much narrower. The reason for this was that the seed source was based on a mode-locked Ti:sapphire laser, which exhibited a much lower phase noise compared to fiber-based laser oscillators.…”

Parallel fiber amplifiers with carrier–envelope drift control for coherent combination of optical frequency combs

“…The rapid developments of reliable double-clad optical fiber with excellent thermo-optical properties and cost-efficient high-power laser diodes have enabled the fiber amplifier to compete with the solid-state amplifier in building highpower ultrashort laser system toward the kilowatt level [11][12][13][14]. Infrared high-power frequency combs with millihertz linewidths and long-term stable operation have been reported by using cascade fiber optical amplifiers in either feedback [15,16], or feed-forward CE phase control schemes [17][18][19]. However, with the increase of the output power, phase noise caused by the amplitude-to-phase conversion, temporal pulse broadening and spectral distortion caused by the accumulated high-order dispersions and nonlinear effects in the cascade amplifier schemes have become severe problems [20].…”

Pump-induced carrier envelope offset frequency dynamics and stabilization of an Yb-doped fiber frequency comb

“…[7,8] In various existing technologies, the Ybfiber frequency comb has attracted considerable interests for its low-cost direct diode pump, inherent robustness of fiber system, and suitability for high-power amplification. [9][10][11] Until now, the Yb-doped fiber frequency comb can reach an average power up to 100 W, [12] which makes it feasible to realize a phase coherent extreme ultraviolet (XUV) source with photon energy of 100 eV. [13] Besides, the second or fourth harmonics [12,14] are spectrally overlapped with some important narrow linewidth optical transitions, such as Al + (267 nm), Hg + (281.5 nm), and Yb (578.4 nm), which are excellent candidates for the next-generation frequency standard.…”