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.
ABSTRACT
The rise of 2D materials since the discovery of graphene has been exponential. Their mechanical, electrical and optical properties are exceptional, similar to their 3D counterparts. In this paper, an α-In2Se3 crystal is mechanically exfoliated and transferred directly onto a fiber ferrule to serve as a saturable absorber (SA). A thulium-doped fluoride fiber is used as a gain medium to generate mode-locked pulses together with the In2Se3-based SA. The SA has a modulation depth of 14.6% and a saturation intensity of 0.4 kW/cm2. The passively generated mode-locked pulses have a repetition rate of 6.93 MHz and a pulse width of 5.79 ps. The mode-locked pulses also have a signal-to-noise ratio of 65.4 dB and a time-bandwidth product of 0.36. The pulse energy and peak power are 0.179 nJ and 27.2 W, respectively.
