1.3\xa0\xb5m dissipative soliton resonance generation in Bismuth doped fiber laser

H Ahmad,J K Sahu,Y Wang,S N Aidit,M Z Samion,A K Zamzuri,S Wang,S I Ooi

doi:10.1038/s41598-021-85423-y

Abstract

In this work, a Figure-9 (F9) bismuth-doped fiber laser (BiDFL) operating in the dissipative soliton resonance (DSR) regime is presented. The 1338 nm laser used a BiDF as the active gain medium, while a nonlinear amplifying loop mirror (NALM) in an F9 configuration was employed to obtain high energy mode-locked pulses. The wave breaking-free rectangular pulse widened significantly in the time domain with the increase of the pump power while maintaining an almost constant peak power of 0.6 W. At the maximum pump power, the mode-locked laser delivered a rectangular-shaped pulse with a duration of 48 ns, repetition rate of 362 kHz and a radio-frequency signal-to-noise ratio of more than 60 dB. The maximum output power was recorded at around 11 mW with a corresponding pulse energy of 30 nJ. This is, to the best of the author’s knowledge, the highest mode-locked pulse energy obtained at 1.3 μm as well as the demonstration of an NALM BiDFL in a F9 configuration.

Highlights

In this work, a Figure-9 (F9) bismuth-doped fiber laser (BiDFL) operating in the dissipative soliton resonance (DSR) regime is presented
There has been an increased effort to generate high energy, rectangular-shaped mode-locked pulses for the use in all-optical square-wave clocks[7], laser micromachining[8] and optical sensing[9] applications. These rectangular pulses are normally obtained from a mode-locked fiber laser operating in the dissipative soliton resonance (DSR) regime. These type of pulses were initially obtained in the frame of the cubic-quintic complex Ginzburg–Landau equation[10], where the width of the mode-locked pulse in the DSR regime increases with the pump power without pulse breaking, while simultaneously keeping the peak power at a constant level
Note that a mode-locked laser operating in the noise-like pulse (NLP) regime could generate a flat-top rectangular pulse, whose pulse dynamics are very similar to that of DSR pulse

Summary

Experimental setup

The BiDF had core and cladding diameters of 9 and 125 μm, respectively It has a group velocity dispersion (GVD) of approximately − 0.3 ps2/km at 1338 nm[53]. The two output ports of the 3 dB coupler (port 3 and 4 in Fig. 1) are connected together with an isolating element and an additional tapped coupler, forming a unidirectional loop. This passive unidirectional loop was not required in the F9 laser configuration, which simplifies the laser construction. The unidirectional functionality in the F9 was achieved by reflecting the pulse that exits the NALM loop through the FM, ensuring feedback to the laser resonator

Results and discussion

Methods

Conclusion