As the last element in Group VA, bismuthene has garnered substantial interest for its unique electronic and mechanical properties and its enhanced stability. However, the mechanism that drives the light-bismuthene interaction remains completely unclear. Herein, a sonochemical exfoliation approach is employed to deliver a successful synthesis of few-layer bismuthene. The corresponding nonlinear optical response at the visible wavelength is investigated. The nonlinear refractive index is ß10 −6 cm 2 /W and was measured by spatial self-phase modulation. Thanks to its direct energy band-gap at 1550 nm, the saturable absorption property of bismuthene is experimentally illustrated at the telecommunication band with an optical modulation depth of ß2.03% and a saturable intensity of ß30 MW/cm 2 . The optimization of the laser parameters resulted in the generation of an ß652-femtosecond optical pulse centered at 1559.18 nm. This result indicates that the bismuthene-based saturable absorber is indeed a new and excellent material for an ultrafast saturable absorber device. Our work highlights the promise of this material in ultrafast photonics and may be considered as an important step towards bismuthene-based photonics devices (optical modulator, optical switcher, detector, etc.).

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All‐optical modulators, wherein signal light can be manipulated by another controlling light, have recently emerged as a promising perspective in all‐optical communications, interconnects and signal processing. Herein, by taking advantage of the strong light‐matter interaction and thickness‐dependent direct energy bandgap in few‐layer phosphorene, an all‐fiber all‐optical modulator based on a Mach–Zehnder interferometer comprising few‐layer fluorinated phosphorene‐deposited microfiber has been devised and further demonstrated with phase modulation ability. The phase shift of the signal light, capable of being converted into intensity modulation, could be readily controlled by the photothermal effect in phosphorene. A maximal phase shift of 8π is obtained at a control light of 290 mW, corresponding to a conversion efficiency of 0.029 π mW−1. The optical information carried by the control light is successfully copied towards the signal light with a modulation depth of 17 dB and a rise time constant of 2.5 ms. Stability under ambient conditions is enhanced significantly thanks to atomistic fluorination in phosphorene that can overcome drawbacks of easy oxidation of intrinsic phosphorene and maintain performance for a long term. This prototypical phosphorene‐based all‐optical phase modulator will have a great potential to be applied in all‐optical information processing and be integrated into optical fiber systems.

For VO-based thermochromic smart windows, high luminous transmittance (T) and solar regulation efficiency (ΔT) are usually pursued as the most critical issues, which have been discussed in numerous researches. However, environmental durability, which has rarely been considered, is also so vital for practical application because it determines lifetime and cycle times of smart windows. In this paper, we report novel VO@ZnO core-shell nanoparticles with ultrahigh durability as well as improved thermochromic performance. The VO@ZnO nanoparticles-based thermochromic film exhibits a robust durability that the ΔT keeps 77% (from 19.1% to 14.7%) after 10 hours in a hyperthermal and humid environment, while a relevant property of uncoated VO nanoparticles-based film badly deteriorates after 30 h. Meanwhile, compared with the uncoated VO-based film, the VO@ZnO-based film demonstrates an 11.0% increase (from 17.2% to 19.1%) in ΔT and a 31.1% increase (from 38.9% to 51.0%) in T. Such integrated thermochromic performance expresses good potential for practical application of VO-based smart windows.

logic operations, and buffering, are still lacking in practically usable forms. It is still challenging to improve the optical device performance for practical applications, including reducing footprint size, required optical power levels, and device performance regarding nonlinear transfer characteristics. Wavelength conversion between adjacent channels is one of the essential functions in advanced optical networks. As a crucial component in the optical communication system, alloptical wavelength converter should be with advantages of high speed, bit rate transparency, low chirp, and no extinction ratio degradation. [4,5] Wavelength conversion in the optical system was typically realized by utilizing the parametric nonlinear optical effect, including cross gain modulation (XGM), [6] four-wave mixing (FWM), [7][8][9][10][11][12][13] and cross phase modulation (XPM) effect. [14,15] These nonlinear optical wavelength converters were typically realized in semiconductor optical amplifiers (SOA). [6] By using the SOAs, the XGM-based method is highly power efficient and polarization independent but suffers from high extinction ratio degradation. Besides, only converted signal can be obtained in the desired wavelength through the XGM-based method. The XPM-based method can convert signal to the target wavelength with converted signal into a SOA-Mach-Zehnder interferometer structure. [16] However, the input power of the XPM-based method is limited in a certain range and has to be integrated. FWM method is attractive because it is transparent to modulation format and capable of transmitting high bit rate signals. [6] FWM methods typically suffer from low conversion efficiency and fast decrease on efficiency as wavelength span increases. Researchers have also investigated other nonlinear optical methods to realize the wavelength conversion, such as highly nonlinear optical fiber, [17] nonlinear optical loop mirror, [18] optical filtering, [19] or based on time-domain holography [20] and so on. These previous methods suffer from high cost, unstable, bulky, or difficult to be compatible in the fiber system.In the last decade, novel materials-based optical devices are considered as an effective solution. Silicon was considered to be with great potential in the optical signal processing system as it is transparent at the near-and mid-infrared telecommunication regime and with high nonlinearity. [21][22][23][24] Silicon waveguides have been reported as optical wavelength converter in the photonic signal processing system. [25,26] For the all-optical applications utilizing the third-order nonlinear properties of Optical signal processing based on 2D materials is a hot topic which has attracted rising interests. As a novel class of 2D material, MXene is becoming a promising nonlinear photonics material. In this contribution, MXene Ti 3 C 2 T x , prepared by liquid acid etching method, is developed as a novel all-optical device by depositing on a microfiber, which shows an excellent nonlinear optical response at the telecommunicati...

Ultrafast Photonics Bismuthene has garnered substantial interest for its unique electronic and mechanical properties, and enhanced stability. However, the mechanism that drives the interaction between light and bismuthene remains unclear. In article number 1700221, Han Zhang and co‐workers synthesize few‐layer bismuthene and investigate the nonlinear optical properties by spatial self‐phase modulation measurement based on sonochemical approaches.

The present study aimed to investigate whether Lycium barbarum polysaccharides (LBP) would protect against doxorubicin (DOX)-induced testicular toxicity. Male Sprague-Dawley rats were treated with distilled water (4 mL/kg) or LBP (200 mg/kg, p.o.) daily for 10 days and followed by saline (0.9 %, 10 mL/kg) or DOX (10 mg/kg) intravenous injection at day 7. Pretreatment with LBP ameliorated DOX-induced reduction in the testicular weights, sperm concentrations and percentage of motile sperms, as well as the increase in abnormal sperm rate. LBP administration to DOX-treated rats successfully reversed the changes in MDA and GHS-Px levels. Compared with the control, pretreatment with LBP significantly increased the plasma testosterone level in the LBP + DOX group. The histopathology examinations further confirmed that LBP effectively attenuated DOX-induced severe degenerative changes of seminiferous tubules. This study illustrated the capability of LBP in attenuating testicular oxidative stress and protecting testis-specific toxicity in DOX-exposed rats.

This work reports a VO2/NLETS hybrid film with a 127% increase in ΔTsol and an evident temperature-responsive colour change.