100 W dissipative soliton resonances from a thulium-doped double-clad all-fiber-format MOPA system

Abstract

In this paper, we first achieve nanosecond-scale dissipative soliton resonance (DSR) generation in a thulium-doped double-clad fiber (TDF) laser with all-anomalous-dispersion regime, and also first scale the average power up to 100.4 W by employing only two stage TDF amplifiers, corresponding to gains of 19.3 and 14.4 dB, respectively. It is noted that both the fiber laser oscillator and the amplification system employ double-clad fiber as the gain medium for utilizing the advantages in high-gain-availability, high-power-handling and good-mode-quality-maintaining. DSR mode-locking of the TDF oscillator is realized by using a nonlinear optical loop mirror (NOLM), which exhibits all-fiber-format, high nonlinear and passive saturable absorption properties. The TDF oscillator can deliver rectangular-shape pulses with duration ranging from ~3.74 to ~72.19 ns while maintaining a nearly equal output peak power level of ~0.56 W, namely peak power clamping (PPC) effect. Comparatively, the two stage amplifiers can scale the seeding pulses to similar average power levels, but to dramatically different peak powers ranging from ~0.94 to ~18.1 kW depending on the durations. Our TDF master-oscillator-power-amplifier (MOPA) system can provide a high power 2-μm band all-fiber-format laser source both tunable in pulse duration and peak power.

Tunable and switchable harmonic h-shaped pulse generation in a 303 km ultralong mode-locked thulium-doped fiber laser

“…Thus, for too high an order of HML, the long trailing portion of the h-shaped pulses would fully occupy the pulse intervals, i.e., adjacent pulses would nearly overlap with each other. In the experimental aspect, however, the pulses would typically merge into a continuous wave operation rather than forming a pulse overlap state, like what we observed in our previous publication where the PDC could approach to 98.2% but its further increase would result in the transformation into a continuous wave state [34].…”

“…Relying on wavebreaking-free properties attributed to peak-power-clamping (PPC) effect, DSR has recently been shown as a promising mode-locking regime that could scale the pulse energy to virtually unlimited levels, and, in fact, up to 10 μJ single pulse energy from a fiber laser oscillator was achieved by G. Semaan et al [33]. The detailed amplifying characteristics of DSR pulses at 2 μm band were investigated by J. Zhao et al, where over 94 μJ amplified pulse energy was obtained with up to ~18.4 kW peak power from a thulium-doped fiber (TDF) master oscillator power amplifier (MOPA) system [34]. However, despite the unparalleled scalability in single pulse energy, the HML was still observed in the DSR regime [28,29,35].…”

Picosecond Yb-doped tapered fiber laser system with 1.26 MW peak power and 200 W average output power

“…As can be seen from Fig. 7, a signal amplification leads to a broadening of its spectrum 17 . To calculate pulse energy correctly, we have determined percentage of spectral power in the signal band.…”

Route to Larger Pulse Energy in Ultrafast Fiber Lasers

“…Due to the low peak power, DSR pulses are perfect candidate for amplification. Amplified DSR pulses of tens of micro-Joules have been demonstrated [61]. DSR pulses can also be achieved in an all-polarization-maintaining fiber laser [62].…”