Highly-stable mode-locked PM Yb-fiber laser with 10 nJ in 93-fs at 6 MHz using NALM

Abstract

We demonstrate highly stable mode-locked Yb-doped fiber oscillators using a nonlinear amplifying loop mirror, delivering linearly polarized laser pulses with high energy at a low repetition rate of several MHz. These lasers are composed of polarization-maintaining fibers and fiber-based components without intra-cavity dispersion compensation. The spectral and temporal characteristics are systematically investigated at different repetition rates. Spectral bandwidth of 31 nm is realized in the case of 6 MHz repetition rate, and the pulse energy reaches 10 nJ. A pair of gratings compresses the output pulse to 93 fs. RMS power stability is as low as 0.04% in 10 hours, which shows excellent stability. We believe that this type of fiber oscillator is an ideal seed for further high power amplification.

27nJ, 114fs Pulses From an Environmentally Stable All-Normal All-PM Yb-Doped Fiber Laser Mode-Locked With a Nonlinear Amplifying Loop Mirror

“…It is also possible to improve the output parameters by optimizing the structure of the laser cavity. By optimizing the repetition rate, a 6-MHz all-PM fiber oscillator delivering 10nJ pulses with 31nm spectral bandwidth which can be compressed to 93fs was demonstrated [17]. Deng et al optimized the position of gain fiber in the NALM loop and achieved a 22nJ pulse output that can be compressed to 195 fs [18].…”

Energy Scaling of an Ultrafast All-PM-Fiber Laser Oscillator

“…However, in the presented configuration, a piece of single-mode fiber (SMF) was used for building the mode-locker, which decreased the robustness of the setup. Also a hybrid configuration, incorporating both SMF and PM fibers, was presented by Yu et al who obtained 10 nJ pulses using NALM as a saturable absorber [21]. Pulses with the energy of 4.2 nJ from an environmentally stable all-PM fiber oscillator using NALM as artificial SA were presented by Aguergaray et al [19].…”

All Polarization-maintaining Passively Mode-locked Ytterbium-doped Fiber Lasers, Behavior under Two Different Cavity Configurations

“…Here we review our most recent works in the field of passively mode-locked ytterbiumdoped fiber lasers delivering DSs light pulses, in two different cavity configurations, namely fiber-ring and Fabry-Perot [8,9]. Further, the different DSs PM fiber lasers presented to date all have in common the use of strong filtering within the cavity by using either bandpass pigtailed PM filters, tilted fiber Bragg gratings, or chirped fiber Bragg gratings [10,11,12,13,14,15,16,17]. Examples in the literature without a specific filter in an ANDi PM Yb-doped fiber laser are scarce, and with output light pulses well in the nanoseconds range [18].…”