Large reversible upconversion luminescence modification and 3D optical information storage in femtosecond laser irradiation-subjected photochromic glass

Fast response,high luminescence contrast,three-dimensional(3D)storage,and nondestructive reading are key factors for the optical storage application of photochromic materials.Femtosecond(fs)laser direct writing technology with multiphoton nonlinear absorption is becoming a useful tool for microprocessing functional units in the 3D space of glass owing to its remarkable advantages,such as a fast processing speed and high processing accuracy.Herein,the photochromism of transparent glass codoped with rare-earth ions was investigated under 800-nm fs laser irradiation,affording a fast response.The photochromic glass achieves an upconversion luminescence(UCL)modification of 92%.The photochromic glass can be bleached back to its original color using heat treatment.The transmittance and UCL modification show excellent reproducibility under alternating stimulations between 800-nm fs laser irradiation and heat treatment.The data can be written in the interior of the transparent photochromic glass using 800-nm fs laser irradiation,facilitating 3D information storage.These results suggest that the 800-nm fs laser irradiation-subjected photochromic glass is an ideal optical data storage medium.

Reversible multiplexing for optical information recording, erasing, and reading-out in photochromic BaMgSiO4:Bi3+ luminescence ceramics

Optical data storage technology has many advantages over the traditional solid-state and magnetic storage technology,such as low cost,multi-dimensional storage,and rewritable capability.Therefore,the optical data storage technology has been in increasing demand for optical storage media.Herein,the photochromic and photoluminescence properties of BaMgSiO4:Bi^3+ceramics were investigated.The BaMgSiO4:Bi^3+ceramics showed reversible photochromism from gray to pink upon alternating the 254 nm ultraviolet light and 532 nm laser irradiation.This is caused by the electron trapping and de-trapping in the oxygen vacancies of the BaMgSiO4:Bi^3+host.This reversible behavior of photochromism was applied to fabricate different patterns on the surface of the BaMgSiO4:Bi^3+ceramics,which exhibited the reversible dual-mode optical information recording and erasing abilities.The photoluminescence reversible modulation of the BaMgSiO4:Bi^3+ceramics was obtained through the photochromic phenomenon.This modification behavior of luminescence could be applied to read-out the recording information in the BaMgSiO4:Bi^3+ceramics.The coloration and bleaching of BaMgSiO4:Bi^3+ceramics were dependent on the time of light stimulation,which facilitated multiplexing encoding.This photoluminescence and photochromism multiplexing of the BaMgSiO4:Bi^3+ceramics enhanced the optical data storage capability.

Reversibly switching the conformation of short peptide through in-tether chiral sulfonium auxiliary

A chirality induced helicity method has been developed to modulate the peptide＇s biophysical and biochemical properties. We report herein a novel approach for reversibly switching the conformation of short constraint a-helical peptides through alkylation of the in-tether thioether and dealkylation of the chiral sulfonium. This traceless redox sensitive tagging strategy broadened our scope of CIH （chirality induced helicity） strategy and provided a valuable approach to functionalize the peptide tether.