Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This pa...Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This paper develops a long-period fiber grating sensor based on periodic microchannels.First,a series of linear structures were etched in the cladding of a single-mode fiber by femtosecond laser microma-chining.Then,the laser-modified region was selectively eroded by selective chemical etching to obtain the periodic microchannel structure.Finally,the channels were filled with polydimethylsiloxane(PDMS)to im-prove the spectral quality.The experimental results show that the sensor has good sensitivity in the measure-ment of various parameters such as temperature,stress,refractive index(RI),and bending.It has a temperat-ure sensitivity of−55.19 pm/℃,a strain sensitivity of−3.19 pm/με,a maximum refractive index sensitivity of 540.28 nm/RIU,and a bending sensitivity of 2.65 dB/m^(-1).All of the measurement parameters show good lin-ear responses.The sensor has strong application prospects in the field of precision measurement and sensing.展开更多
Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but rema...Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but remains a great challenge.Here,we report the efficient white emission from Au_(10) NCs by elaborately deploying the surface chemistry engi⁃neering strategy.Specifically,the bis-aldehyde ligands of 4-hydroxyisophthalaldehyde(HOA)are decorated on the surface of Au_(10)(SG)_(10) NCs(glutathione denoted as SG)through the cross-linking reaction of imine bonds(-CH==N-).The combination of 477 nm blue emission from HOA ligands and 620 nm orange-yellow emission from Au_(10)(SG)_(10) NCs generates white-light emission in HOA-Au_(10)(SG)_(10) NCs in the solvent mixture of ethanol and water.More importantly,dynamic color tuning from blue light to yellow light is achieved by controlling the volume fraction of ethanol in the solvent mixture.In addi⁃tion,the as-formed imine bonds significantly improve the structural rigidity of HOA-Au_(10)(SG)_(10) NCs,resulting in the 51.2%absolute photoluminescence quantum yield(PLQY)of white emission.The present study exemplifies the paradigm to control the emission color and improve the PLQY of metal NCs through rational surface chemistry engineering.展开更多
文摘Long-period fiber gratings have the advantages of small size,corrosion resistance,anti-electro-magnetic interference,and high sensitivity,making them widely used in biomedicine,the power industry,and aerospace.This paper develops a long-period fiber grating sensor based on periodic microchannels.First,a series of linear structures were etched in the cladding of a single-mode fiber by femtosecond laser microma-chining.Then,the laser-modified region was selectively eroded by selective chemical etching to obtain the periodic microchannel structure.Finally,the channels were filled with polydimethylsiloxane(PDMS)to im-prove the spectral quality.The experimental results show that the sensor has good sensitivity in the measure-ment of various parameters such as temperature,stress,refractive index(RI),and bending.It has a temperat-ure sensitivity of−55.19 pm/℃,a strain sensitivity of−3.19 pm/με,a maximum refractive index sensitivity of 540.28 nm/RIU,and a bending sensitivity of 2.65 dB/m^(-1).All of the measurement parameters show good lin-ear responses.The sensor has strong application prospects in the field of precision measurement and sensing.
文摘Photoluminescence(PL)is one of the most important properties of metal nanoclusters(NCs).Achieving effi⁃cient white light emission in metal NCs with a precise structures is important for practical applications but remains a great challenge.Here,we report the efficient white emission from Au_(10) NCs by elaborately deploying the surface chemistry engi⁃neering strategy.Specifically,the bis-aldehyde ligands of 4-hydroxyisophthalaldehyde(HOA)are decorated on the surface of Au_(10)(SG)_(10) NCs(glutathione denoted as SG)through the cross-linking reaction of imine bonds(-CH==N-).The combination of 477 nm blue emission from HOA ligands and 620 nm orange-yellow emission from Au_(10)(SG)_(10) NCs generates white-light emission in HOA-Au_(10)(SG)_(10) NCs in the solvent mixture of ethanol and water.More importantly,dynamic color tuning from blue light to yellow light is achieved by controlling the volume fraction of ethanol in the solvent mixture.In addi⁃tion,the as-formed imine bonds significantly improve the structural rigidity of HOA-Au_(10)(SG)_(10) NCs,resulting in the 51.2%absolute photoluminescence quantum yield(PLQY)of white emission.The present study exemplifies the paradigm to control the emission color and improve the PLQY of metal NCs through rational surface chemistry engineering.
