Switchable generation of a sub-200  fs dissipative soliton and a noise-like pulse in a normal-dispersion Tm-doped mode-locked fiber laser

Abstract

We report on the switchable generation of a dissipative soliton (DS) pulse and a noise-like pulse (NLP) in an all-fiberized Tm-doped fiber laser in the normal-dispersion region. Mode-locking operation is achieved through a nonlinear polarization rotation component, and the cavity dispersion is compensated using ultra-high numerical aperture (UHNA4) fiber that is easy to integrate and low in cost. At a pump threshold of 510 mW, DS operation can first be achieved without additional filter. The 3 dB spectrum bandwidth of the DS pulse is greater than 50 nm, and the duration of the de-chirped pulse is 193 fs. By increasing the pump power to 880 mW, the mode-locking state can evolve into NLP operation with proper cavity polarization state. The 3 dB spectrum bandwidth and duration of de-chirped coherence spike are 105.6 nm and 121 fs, respectively. Meanwhile, ultra-broadband NLP (over 150 nm considering 3 dB spectrum width) can also be observed with the appropriate cavity parameters. All the proposed pulse patterns present good capacity for achieving narrow pulse width and withstanding high pulse energy.

Noise-like pulses from all-normal dispersion ytterbium doped all-fiber oscillator with semiconductor saturable absorber

“…Hence there is a clear distinction between NLP and SSCP profiles in shot to shot recording as can be seen from figure 4. It is worth to mention here that earlier reports on NLP generation using NPR based SA, both SSCP and NLP could be generated from the same cavity by adjustment of the biasing of NPR using polarization controllers [28,29]. However, with our best effort no SSCP could be generated from the laser setup.…”

Generation and Dynamics of Multiple Pulses in an Ultrafast Fiber Laser with a Single-Mode Fiber–Graded-Index Multimode Fiber–Single-Mode Fiber-Based Saturable Absorber

“…It can be seen from Figure 7b that the average output power climbs from 6.01 mW to 32.4 mW as the pump power rises from 165 mW to 665 mW in the multiple-pulse operation. It is difficult to precisely calculate the pulse energy of the special multiple pulse operation state because there are multiple pulses with varying pulse numbers, peak power and pulse width [45,46]. However, we can estimate the pulse energy of multi-pulses by dividing the average output power by the repetition frequency [47,48].…”

Noise-like pulses with an h-shape from a 2 μm semiconductor saturable-absorber mirror mode-locked fiber oscillator

“…The first report of NLPs in a thulium-doped fiber laser (TDFL) was in 2011 [19]. Several recent reports have focused on the internal correlation between NLP mechanisms and soliton mechanisms [20][21][22][23].…”