In-fiber photoelectric device based on graphene-coated tilted fiber grating

Graphene and related two-dimensional materials have attracted great research interests due to prominently optical and electrical properties and flexibility in integration with versatile photonic structures.Here,we report an in-fiber photoelec-tric device by wrapping a few-layer graphene and bonding a pair of electrodes onto a tilted fiber Bragg grating(TFBG)for photoelectric and electric-induced thermo-optic conversions.The transmitted spectrum from this device consists of a dense comb of narrowband resonances that provides an observable window to sense the photocurrent and the electrical injection in the graphene layer.The device has a wavelength-sensitive photoresponse with responsivity up to 11.4 A/W,allowing the spectrum analysis by real-time monitoring of photocurrent evolution.Based on the thermal-optic effect of electrical injection,the graphene layer is energized to produce a global red-shift of the transmission spectrum of the TF-BG,with a high sensitivity approaching 2.167×10^(4)nm/A^(2).The in-fiber photoelectric device,therefore as a powerful tool,could be widely available as off-the-shelf product for photodetection,spectrometer and current sensor.

Development of Phase-Field Modeling in Materials Science in China:A Review

Phase-field method,as a powerful and popular approach to predict the mesoscale microstructure evolution in various materials science,provides a bridge from atomic-scale methods to the macroscale and has been widely used at an ever-increasing rate.This paper aims to briefly review the origin,basic idea,and development of phase-field models in a historical manner.The focus is placed on the classical and state-of-the-art applications in China,including liquid–solid,solid–solid,gas–solid,ferroelectrics/ferromagnetics phase transformation,and crack propagation-fracture.After introducing the academic activities in the phase-field community in China,some suggestions for the future development directions of phase-field method are finally mentioned.

Spherical Particles Growth with Dynamic Oscillation during Lithium Electrodeposition

In this paper,the spherical particles growth during lithium electrodeposition was investigated by directly solving the governing equations based on the Landau transformation method.The basic growth kinetic characteristics of a spherical particle during electrodeposition was studied.Predicted results show that the dynamic oscillation of the growth velocity occurs during the spherical particle growth.It was found from numerical simulations that applied electrical potential difference,electrolyte concentration,and diffusion coefficient are 3 main factors influencing the spherical growth and the existence of the dynamic oscillation state of the growth velocity during electrodeposition.The increase in both the applied electrical potential difference and the electrolyte concentration can lead to the increase of the growth velocity of the spherical particle,while the growth velocity is independent of the diffusion coefficient.Moreover,it was found that the wavelength and the amplitude of the dynamic oscillation of the growth velocity can be influenced by the applied electrical potential difference,the electrolyte concentration,and the diffusion coefficient.We determined that the dynamic competition between electrochemical reactions and ion transport in the electrodeposition is the reason for the existence of the oscillation of the growth velocity.