Generation and evolution of multiple operation states in passively mode-locked thulium-doped fiber laser by using a graphene-covered-microfiber

Abstract

Using graphene-covered-microfiber (GCM) as a saturable absorber, the generation and evolution of multiple operation states are proposed and demonstrated in passively mode-locked thulium-doped fiber laser. The microfiber was fabricated using the flame brushing method to an interaction length of ∼ 1.2 cm with a waist diameter of ∼ 10 µm. Graphene layers were grown on copper foils by chemical vapor deposition and transferred onto the polydimethylsiloxane (PDMS) to form a PDMS/graphene film, which allowed light-graphene interaction via evanescent field. With the increase of the pump power from 1.25 W to 2.15 W, five different lasing regimes, including continuous-wave, conventional soliton mode-locking, multisoliton mode-locking, a period of transition, and noise-like mode-locking, were achieved in a fiber ring cavity. To the best of our knowledge, it is the first report of the generation and evolution of multiple operation states by covering graphene on the microfiber in the 2-µm region. The results demonstrate that GCM can be a promising method for fabricating all fiber SA, and the switchable operation states can provide more portability in complex application domain.

Graphene-Coated Nanowire Waveguides and Their Applications

“…Yao et al [113] demonstrated a compact all-in-line graphene-based distributed feedback Bragg-grating fiber laser with narrow linewidth based on GCNWs. In 2018, Wang et al [114] reported that using a graphene-coated microfiber saturable absorber, the generation and evolution of multiple operation states were proposed and demonstrated in passively mode-locked thulium-doped fiber laser. Recently, Li et al [115] reported an active-passive Q-switched laser based on graphene-covered microfiber, which not only served as a passive saturable absorber in a single laser cavity, but also could be used as an all-optical modulation device.…”

Generation of cavity-birefringence-dependent multi-wavelength bright–dark pulse pair in a figure-eight thulium-doped fiber laser*

“…To date, there have been a lot of reports on mode-locked fiber lasers. By managing the parameters of the fiber resonator, different kinds of pulses, such as conventional solitons, [1] dissipative solitons, [2] vector solitons, [3,4] rectangular-shaped pulses, [5,6] chair-like pulses, [7] and h-shaped pulses [8] have been experimentally observed in passively mode-locked fiber lasers. However, the above pulses are all bright pulses.…”

Generation of wide-bandwidth pulse with graphene saturable absorber based on tapered fiber

“…[19][20][21][22][23] Among these integration methods, the ones based on evanescent field interaction, such as graphene-tapered-fiber (GTF) SAs, are popular in the research of graphene mode-locking devices owing to their high damage threshold, long interaction length, and convenient manufacture. [24,25] Several researches on mode-locked fiber lasers using GTF SAs have been reported. These studies have various concerns, such as multiwavelength operation, [26] tunablebandwidth mode-locked fiber lasers, [16] SAs with tunable modulation depth [27] and high output power.…”