Investigation of noise-like pulses from a net normal Yb-doped fiber laser based on a nonlinear polarization rotation mechanism

Abstract

We investigated the characteristics of noise-like pulses (NLPs) from a net normal dispersion Yb-doped fiber laser (YDFL) by using the grating pairs (GPs) inside the laser cavity as a dispersion compensation element. Without the insertion of the slit inside the laser cavity, the operation of the YDFL is at an NLP state with the double-scale intensity autocorrelation trace once the mode-locked pulses are generated. Through the dispersion delay line outside the laser cavity, the substantial temporal compression of the NLPs has been demonstrated. After inserting the slit between the GPs as a bandpass filter, the operation state of the YDFL can be switched between the NLPs and the dissipated solitons by means of a pump power. Besides, the NLPs can also transit to the bound solitons as the YDFL is operated within long and short wavelength regimes through the spatial shift of the slit.

Numerical study of multiple noise-like pulsing in a dispersion-managed figure-eight fibre laser

“…One first striking observation is the ample fluctuations in the temporal extension of each bunch over one cycle (see figure 3(a1), close-up on bunch 5). This is interesting as it contradicts the common belief that NLPs are nearly uncompressible, and shows that they can actually be compressed by a rather large factor; this result is also consistent with the recent experimental demonstration of NLP compression by a factor of ~10 [57]. Actually, the evolution of figure 3(a) is comparable to that of the solitons that form in dispersion-managed cavities known as stretched-pulse fibre lasers (SPFL) [58].…”

Noise-like pulses with 2.15 MHz repetition rate in an all-polarization-maintaining mode-locked fiber laser at the center wavelength of 1550 nm

“…Next, we observe the change in the autocorrelation traces by adjusting the pump power and adding a spool of single-mode fiber (SMF) (17 ps nm −1 km −1 at 1550 nm) outside the cavity to compress the pulse, as previously carried out in [41,42]. It can be seen from figure 4 that when the pump power increase from 200 mW to 550 mW, the height of peak and rectangular shoulder of the autocorrelation trace are constantly increasing.…”

Pump power induced instability and hysteresis in an all-normal dispersion linear mode-locked fiber laser

“…CW lasing at a central wavelength of 1064 nm has been obtained at a pump power of 46 mW and transition to a stable mode-locked state occurred at 96 mW pump power. The OSA spectrum in a mode-locked state centered at 1064 nm exhibited steep edges which are the key characteristics of dissipative soliton in an ANDi cavity [25]. With increasing the pump power, the spectral width (10 dB) gradually increases from 2.1 nm to 2.5 nm and then a sudden increase occurs beyond 115 mW pump power.…”