Passively Q-switched mid-infrared fluoride fiber laser around 3µm using a tungsten disulfide (WS₂) saturable absorber

Abstract

In this letter, we demonstrate a passively Q-switched Ho3+/Pr3+ co-doped fluoride fiber laser centered at 2865.7 nm using a tungsten disulfide (WS2) saturable absorber (SA) for the first time, to the best of our knowledge. A multilayer WS2 film was fabricated using the sulfidation grown method and then transferred onto an Au mirror to act as the cavity feedback and SA device in a linear cavity. Under a launched pump power of 318.5 mW, stable Q-switched pulses with an average output power of 48.4 mW were achieved with a pulse duration of 1.73 µs and repetition rate of 131.6 kHz, resulting in a pulse energy of 0.37 µJ. Our experimental results confirm that WS2 can be an effective nonlinear modulator that is suitable for pulse generation at the 3 µm waveband.

Nonlinear optics of two‐dimensional transition metal dichalcogenides

“…Figure A shows a typical saturation absorption of MoS 2 at 1060 nm . Recently, numerous Q‐switch and mode‐locking function were realized with MoS 2 , WS 2 , MoSe 2 , and WSe 2 based SA with wideband, tunable repetition, and tunable pulse duration.…”

Q-switched Dy:ZBLAN fiber lasers beyond 3 μm: comparison of pulse generation using acousto-optic modulation and inkjet-printed black phosphorus

“…A number of recent works have successfully applied nanomaterials for mid-IR saturable absorption and pulse generation, including using graphene [5,32], Dirac semi-metal Cd 3 As 2 [33], transition metal dichalcogenides (e.g. WS 2 ) [34] and black phosphorus (BP) [11,35]. Of these, there is particular interest in BP for mid-IR nonlinear photonics as it is a layered material that possesses a thickness-dependent direct bandgap, varying from 0.3 eV (∼4.1 µm) in bulk form (i.e.…”

Self-Q-switched and wavelength-tunable tungsten disulfide-based passively Q-switched Er:Y2O3 ceramic lasers

“…Recently, as a member of TMD family, WS 2 has been developed as a saturable absorber. Similar to MoS 2 , defects, boundary effects, and impurities of WS 2 could modify its bandgap structure, decreasing from 1.18 to 0.02 eV (61.6 μm) and 0.65 eV (1.89 μm) by suitably introducing W and S defects, respectively [23]. As a consequence, WS 2 should exhibit broadband saturable absorption properties, which deserves in-depth investigations.…”

“…This situation is now changing with the development of 2D materials that have been reported to have advantages such as ultrabroadband saturable absorption, low cost, and easy fabrication. These merits have made 2D materials very popular for Q-switched and mode-locked laser operation from the visible to mid-infrared wavelength ranges [16][17][18][19][20][21][22][23][24][25][26][27][28]. In fact, in terms of passively Q-switched mid-infrared lasers as the investigated topic in this work, recently graphene [21], MoS 2 [22], tungsten disulfide (WS 2 ) [23], MoTe 2 [24], ReS 2 [25], Bi 2 Te 3 [26], and black phosphorus (BP) [27,28] have been successfully used as saturable absorbers in the fields of solid-state lasers and/or fiber lasers.…”