Few-layer bismuthene is an emerging two-dimensional material in the fields of physics, chemistry, and material science. However, its nonlinear optical property and the related photonics device have been seldom studied so far. Here, we demonstrate a sub-200 fs soliton mode-locked erbium-doped fiber laser (EDFL) using a microfiber-based bismuthene saturable absorber for the first time, to the best of our knowledge. The bismuthene nanosheets are synthesized by the sonochemical exfoliation method and transferred onto the taper region of a microfiber by the optical deposition method. Stable soliton pulses centered at 1561 nm with the shortest pulse duration of about 193 fs were obtained. Our findings unambiguously imply that apart from its fantastic electric and thermal properties, few-layer bismuthene may also possess attractive optoelectronic properties for nonlinear photonics, such as mode-lockers, Q-switchers, optical modulators and so on.
Black phosphorous (BP), the most thermodynamically stable allotrope of phosphorus, fills up the lacuna left by other two-dimensional materials with a band gap from 0.3 to 2 eV.
Flexible electrochromic devices (FECDs) are extensively
used in
smart windows, deformable electronic displays, and wearable electronics.
However, it remains very challenging to fabricate low-cost yet high-performance
visible–near-infrared (vis–NIR) FECDs. In this work,
we overcome this hurdle by developing a fluorinated polythiophene
derivative with superior overall electrochromic performance and simple
electropolymerization patterning. Fluorophenyl-modified polythiophene
(band gap: 1.74 eV) can be readily synthesized via a one-step Grignard
coupling with a high yield of >90% together with successive low-potential
electropolymerization at 1.0 V vs Ag/AgCl. The intermolecular hydrogen
bonding from the fluorine substitution of polythiophene backbones
allows the facile electrodeposition of free-standing polymer films
with a compact morphology and also leads to mechanical strength and
electrical conductivity enhancement. Interestingly, such polymer films
exhibit intriguing overall electrochromic performances with reversible
color changes between deep red and light green upon doping/dedoping,
including high optical contrast throughout the NIR region (max. 80%
at 1600 nm), fast response time (0.93 s), high coloration efficiency
(up to 752 cm2 C–1), outstanding stability
against cycling (<3% reduction after 5,000 cycles), and excellent
optical memory effect. The fabricated FECDs by electropolymerization
patterning of such polymers display robust mechanical stability (<5%
decay in optical contrast after 5,000 bending cycles with a bending
radius of 1 cm) under a low driving voltage (0.85 V). We further demonstrate
the applications of such patterned electrochromic devices toward deformable
displays, color-changing electronic on-skin tattoos, and infrared
camouflage with stable color-switching and robust mechanical properties.
Based on the saturable absorption feature of a two-dimensional (2D) nano-material, antimonene, the passively Q-switched operation for solid-state laser was realized for the first time. For the 946 and 1064 nm laser emissions of the Nd:YAG crystal, the Q-switched pulse widths were 209 and 129 ns, and the peak powers were 1.48, 1.77 W, respectively. For the 1342 nm laser emission of the Nd:YVO crystal, the Q-switched pulse width was 48 ns, giving a peak power of 28.17 W. Our research shows that antimonene can be used as a stable, broadband optical modulating device for a solid-state laser, which will be particularly effective for long wavelength operation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.