Supplementary document for Femtosecond laser-induced phase transition in VO2 films - 6171202.pdf

Supplemental Documen

Saturation of Two-Photon Absorption in Layered Transition Metal Dichalcogenides: Experiment and Theory

The saturation of two-photon absorption (TPA) in four types of layered transition metal dichalcogenides (TMDCs) (MoS₂, WS₂, MoSe₂, WSe₂) was systemically studied both experimentally and theoretically. It was demonstrated that the TPA coefficient is decreased when either the incident pulse intensity or the thickness of the TMDC nanofilms increases, while TPA saturation intensity has the opposite behavior, under the excitation of 1.2 eV photons with a pulse width of 350 fs. A three-level excitonic dynamics simulation indicates that the fast relaxation of the excitonic dark states, the exciton–exciton annihilation, and the depletion of electrons in the ground state contribute significantly to TPA saturation in TMDC nanofilms. Large third-order nonlinear optical responses make these layered 2D semiconductors strong candidate materials for optical modulation and other photonic applications

Designing Poly(arylene ether sulfone)s with Platinum(II) Acetylide to Regulate Photophysical Properties toward Solid-State Nonlinear Limiters

The exploration of solid-state optical power limiting (OPL) materials based on nonlinear absorption (NLA) with heat resistance is essential and leading-edge. We present two types of poly(arylene ether sulfone)s (PAESs) derived from platinum acetylide, featuring varying conjugation lengths and platinum contents. The platinum-incorporated PAESs exhibit outstanding thermal properties (Tg > 180 °C, Td5% ≥ 400 °C) with easy processing into solid films from solvents. Photophysics, ultrafast transient absorption, Z-scan characterizations, and theoretical calculations reveal an abnormal intersystem crossing and the principle of triplet nonlinear limiting (S0 → S1 → Tx → T1 → Tn). The extended τP caused by the longer conjugated ligand is more critical for NLA compared with the lower ΦP caused by higher Pt contents. PAESs with a longer conjugated ligand exhibit superior intrinsic NLA under limited platinum content, while those with shorter conjugated ligands strike a balance between transparency and NLA. The optical limiting threshold (Fth) of the solid-state film is as low as 1.86 J/cm2. This study involves the preparation of solid-state OPL films using platinum-modified PAESs, revealing an intrinsic link between structure and optical properties

Exfoliation of Stable 2D Black Phosphorus for Device Fabrication

Discovering stabilizers that protect phosphorene from oxidative degradation is critically required for dispersion processing of black phosphorus (BP). It is equally important to also find environmentally friendly, low-cost, and practical exfoliating media. Herein, we demonstrate the yield of remarkably stable phosphorene by coating with a polymer to shield the nanosheets from reaction with water and air. The polymer shell suppresses the rate of BP degradation more efficiently than previously reported systems. We present for the first time a simple kinetic model for exfoliation of BP in polyvinylpyrrolidone (PVP) ethanol solution that appears to quantitatively fit BP exfoliation data, and it illuminates mechanistic aspects of exfoliation. Exfoliated flakes consist of a high level of 51% crystalline single layers that are free from structural disorder or oxidation. A successive centrifugation and redispersion strategy is developed affording dispersions with high phophorene-to-stabilizer ratio, which is very useful for further applications. We also demonstrate that PVP-stabilized phosphorene dispersions possess saturable absorption at both 515 and 1030 nm, which have potential use as ultrafast broadband absorbers. Furthermore, such phosphorene dispersions were processed to prepare new metal/phosphorene nanocomposites that have potential for use as electrocatalysts in electrolytic cells

Bilayered Hybrid Perovskite Ferroelectric with Giant Two-Photon Absorption

Perovskite ferroelectrics with prominent nonlinear optical absorption have attracted great attention in the field of photonics. However, they are traditionally dominated by inorganic oxides and exhibit relatively small nonlinear optical absorption coefficients, which hinder their further applications. Herein, we report a new organic–inorganic hybrid bilayered perovskite ferroelectric, (C₄H₉NH₃)₂(NH₂CHNH₂)­Pb₂Br₇ (<b>1</b>), showing an above-room-temperature Curie temperature (∼322 K) and notable spontaneous polarization (∼3.8 μC cm^–2). Significantly, the unique quantum-well structure of <b>1</b> results in intriguing two-photon absorption properties with a giant nonlinear optical absorption coefficient as high as 5.76 × 10³ cm GW^–1, which is almost two-orders of magnitude larger than those of mostly traditional all-inorganic perovskite ferroelectrics. To our best knowledge, <b>1</b> is the first example of hybrid ferroelectrics with giant two-photon absorption coefficient. The mechanisms for ferroelectric and two-photon absorption are revealed. This work will shed light on the design of new ferroelectrics with two-photon absorption and promote their potentials in the photonic application

Bilayered Hybrid Perovskite Ferroelectric with Giant Two-Photon Absorption

Perovskite ferroelectrics with prominent nonlinear optical absorption have attracted great attention in the field of photonics. However, they are traditionally dominated by inorganic oxides and exhibit relatively small nonlinear optical absorption coefficients, which hinder their further applications. Herein, we report a new organic–inorganic hybrid bilayered perovskite ferroelectric, (C₄H₉NH₃)₂(NH₂CHNH₂)­Pb₂Br₇ (<b>1</b>), showing an above-room-temperature Curie temperature (∼322 K) and notable spontaneous polarization (∼3.8 μC cm^–2). Significantly, the unique quantum-well structure of <b>1</b> results in intriguing two-photon absorption properties with a giant nonlinear optical absorption coefficient as high as 5.76 × 10³ cm GW^–1, which is almost two-orders of magnitude larger than those of mostly traditional all-inorganic perovskite ferroelectrics. To our best knowledge, <b>1</b> is the first example of hybrid ferroelectrics with giant two-photon absorption coefficient. The mechanisms for ferroelectric and two-photon absorption are revealed. This work will shed light on the design of new ferroelectrics with two-photon absorption and promote their potentials in the photonic application

Bilayered Hybrid Perovskite Ferroelectric with Giant Two-Photon Absorption

Perovskite ferroelectrics with prominent nonlinear optical absorption have attracted great attention in the field of photonics. However, they are traditionally dominated by inorganic oxides and exhibit relatively small nonlinear optical absorption coefficients, which hinder their further applications. Herein, we report a new organic–inorganic hybrid bilayered perovskite ferroelectric, (C₄H₉NH₃)₂(NH₂CHNH₂)­Pb₂Br₇ (<b>1</b>), showing an above-room-temperature Curie temperature (∼322 K) and notable spontaneous polarization (∼3.8 μC cm^–2). Significantly, the unique quantum-well structure of <b>1</b> results in intriguing two-photon absorption properties with a giant nonlinear optical absorption coefficient as high as 5.76 × 10³ cm GW^–1, which is almost two-orders of magnitude larger than those of mostly traditional all-inorganic perovskite ferroelectrics. To our best knowledge, <b>1</b> is the first example of hybrid ferroelectrics with giant two-photon absorption coefficient. The mechanisms for ferroelectric and two-photon absorption are revealed. This work will shed light on the design of new ferroelectrics with two-photon absorption and promote their potentials in the photonic application

2-Arylbenzo[<i>b</i>]furan derivatives as potent human lipoxygenase inhibitors

<p>Human lipoxygenases (LOXs) have been emerging as effective therapeutic targets for inflammatory diseases. In this study, we found that four natural 2-arylbenzo[<i>b</i>]furan derivatives isolated from <i>Artocarpus heterophyllus</i> exhibited potent inhibitory activities against human LOXs, including moracin C (<b>1</b>), artoindonesianin B-1 (<b>2</b>), moracin D (<b>3</b>), moracin M (<b>4</b>). In our <i>in vitro</i> experiments, compound <b>1</b> was identified as the most potent LOX inhibitor and the moderate subtype selective inhibitor of 12-LOX. Compounds <b>1</b> and <b>2</b> act as competitive inhibitors of LOXs. Moreover, <b>1</b> significantly inhibits LTB4 production and chemotactic capacity of neutrophils, and is capable of protecting vascular barrier from plasma leakage <i>in vivo</i>. In addition, the preliminary structure–activity relationship analysis was performed based on the above four naturally occurring (<b>1</b>–<b>4</b>) and six additional synthetic 2-arylbenzo[<i>b</i>]furan derivatives. Taken together, these 2-arylbenzo[<i>b</i>]furan derivatives, as LOXs inhibitors, could represent valuable leads for the future development of therapeutic agents for inflammatory diseases.</p

Direct Observation of Degenerate Two-Photon Absorption and Its Saturation in WS₂ and MoS₂ Monolayer and Few-Layer Films

The optical nonlinearity of WS₂ and MoS₂ monolayer and few-layer films was investigated using the <i>Z</i>-scan technique with femtosecond pulses from the visible to the near-infrared range. The nonlinear absorption of few- and multilayer WS₂ and MoS₂ films and their dependences on excitation wavelength were studied. WS₂ films with 1–3 layers exhibited a giant two-photon absorption (TPA) coefficient as high as (1.0 ± 0.8) × 10⁴ cm/GW. TPA saturation was observed for the WS₂ film with 1–3 layers and for the MoS₂ film with 25–27 layers. The giant nonlinearity of WS₂ and MoS₂ films is attributed to a two-dimensional confinement, a giant exciton effect, and the band edge resonance of TPA

Drug Repurposing of Histone Deacetylase Inhibitors That Alleviate Neutrophilic Inflammation in Acute Lung Injury and Idiopathic Pulmonary Fibrosis via Inhibiting Leukotriene A4 Hydrolase and Blocking LTB4 Biosynthesis

Acute lung injury (ALI) and idiopathic pulmonary fibrosis (IPF) are both serious public health problems with high incidence and mortality rate in adults, and with few drugs available for the efficient treatment in clinic. In this study, we identified that two known histone deacetylase (HDAC) inhibitors, suberanilohydroxamic acid (SAHA, <b>1</b>) and its analogue 4-(dimethylamino)-<i>N</i>-[7-(hydroxyamino)-7-oxoheptyl]­benzamide (<b>2</b>), are effective inhibitors of Leukotriene A4 hydrolase (LTA4H), a key enzyme in the biosynthesis of leukotriene B4 (LTB4), across a panel of 18 HDAC inhibitors, using enzymatic assay, thermofluor assay, and X-ray crystallographic investigation. Importantly, both <b>1</b> and <b>2</b> markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose. Detailed mechanisms of down-regulation of proinflammatory cytokines by <b>1</b> or <b>2</b> were determined <i>in vivo</i>. Collectively, <b>1</b> and <b>2</b> would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis