Temporal changes in structure and refractive index distribution of adipose tissue at photo-dynamic/photothermal treatment were studied with OCT in vitro.Ethanol-water solutions of indocyanine green(ICG)and brilliant g...Temporal changes in structure and refractive index distribution of adipose tissue at photo-dynamic/photothermal treatment were studied with OCT in vitro.Ethanol-water solutions of indocyanine green(ICG)and brilliant green(BG)were used for fat tissue staining.CW laser diode(808 nm)and LED light source(442 and 597 nm)were used for ir adiation of stained tissue slices.The data received supporting the hypothesis that photodynamic/photothermal treatment,induces fat cell lipolysis during a certain period of time after light exposure.展开更多
We demonstrate a fiber refractive index(RI) sensor based on an excessively tilted fiber grating(ExTFG)immobilized by large-size plasmonic gold nanoshells(GNSs). The GNSs are covalently linked on ExTFG surface.Ex...We demonstrate a fiber refractive index(RI) sensor based on an excessively tilted fiber grating(ExTFG)immobilized by large-size plasmonic gold nanoshells(GNSs). The GNSs are covalently linked on ExTFG surface.Experimental results demonstrate that both the intensity of the transverse magnetic(TM) and transverse electric(TE) modes of ExTFG are significantly modulated by the localized surface plasmon resonance(LSPR) of GNSs due to the wide-range absorption band. The wavelength RI sensitivities of the TM and TE modes in the low RI range of 1.333–1.379 are improved by ~25% and ~14% after GNSs immobilization, respectively, and the intensity RI sensitivities are ~599%/RIU and ~486%/RIU, respectively.展开更多
Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal...Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500℃, t1=1 h; Т2=950 ℃, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YVO4:Eu^3+ 5 at.% nanophosphor was decreased from 0.64 ms in air(nmed=1) to 0.45 ms in chalcogenide glass As39S61(nmed=2.39).展开更多
Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sour...Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sources, and photo- detectors. Despite many efforts to characterize the propagation parameters of these subwavelength 1D plasmonic waveguides, such as Ag nanowires, large discrepancies exist among available reports owing to their sensitivity to the relative weights of co-existing SPP modes and the lack of a method of decoupling these modes and analyzing them separately. In this work, we develop an interference method to distinguish different SPP modes that are simultaneously excited in a Ag nanowire waveguide and measure their propagation parameters separately. By extracting information from the propagation-distance- dependent intensity oscillations of the scattered light from the nanowire tip, the effective refractive indices, propagation lengths, and relative mode weights of co-existing SPP modes supported by the nanowire are derived from a mode interference model. These parameters depend strongly on the nanowire diameter and excitation wavelength. In particular, we demonstrate the possibility of selective excitation of different SPP modes by varying the nanowire diameter. This new mode analysis technique provides unique insights into the develop- ment and optimization of SPP-based applications.展开更多
In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveg...In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveguide widths in a period,a reflection channel with a large bandwidth is firstly achieved.Besides,the Mach-Zehnder interference(MZI)effect arises by shifting the gratings away from the waveguide center.Owing to different optical paths with unequal indices on both sides of the grating,a narrow MZI band gap will be obtained.It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other,and their wavelengths can be manipulated by the period and the grating length,respectively.Additionally,we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period.The performances are investigated by finite-difference time-domain(FDTD)simulations.In the index range of 1.33–1.36,the maximum sensitivity for the structure is as high as 1500 nm/RIU,and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.展开更多
基金supported by grant No 224014 PHOTONICS4LIFE of FP7-ICT-2007-2,project No 1.4.09,RF Governmental con-tracts 11.519.11.2035,14.B37.21.0728,and 14.B37.21.0563FiDiPro,TEKES Program(40111/11),Finland+1 种基金SCOPES EC,Uzb/Switz/RF,Swiss NSF,IZ74ZO 137423/1RF President's grant 1177.2012.2"Scientific Schools"。
文摘Temporal changes in structure and refractive index distribution of adipose tissue at photo-dynamic/photothermal treatment were studied with OCT in vitro.Ethanol-water solutions of indocyanine green(ICG)and brilliant green(BG)were used for fat tissue staining.CW laser diode(808 nm)and LED light source(442 and 597 nm)were used for ir adiation of stained tissue slices.The data received supporting the hypothesis that photodynamic/photothermal treatment,induces fat cell lipolysis during a certain period of time after light exposure.
基金supported by the National Natural Science Foundation of China(Nos.61875026 and 61505017)the Foundation and Cutting-Edge Research Projects of the Chongqing Science and Technology Commission(No.cstc2018jcyjAX0122)the Graduate Student Innovation Program of the Chongqing University of Technology(No.ycx2018238)
文摘We demonstrate a fiber refractive index(RI) sensor based on an excessively tilted fiber grating(ExTFG)immobilized by large-size plasmonic gold nanoshells(GNSs). The GNSs are covalently linked on ExTFG surface.Experimental results demonstrate that both the intensity of the transverse magnetic(TM) and transverse electric(TE) modes of ExTFG are significantly modulated by the localized surface plasmon resonance(LSPR) of GNSs due to the wide-range absorption band. The wavelength RI sensitivities of the TM and TE modes in the low RI range of 1.333–1.379 are improved by ~25% and ~14% after GNSs immobilization, respectively, and the intensity RI sensitivities are ~599%/RIU and ~486%/RIU, respectively.
文摘Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500℃, t1=1 h; Т2=950 ℃, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YVO4:Eu^3+ 5 at.% nanophosphor was decreased from 0.64 ms in air(nmed=1) to 0.45 ms in chalcogenide glass As39S61(nmed=2.39).
文摘Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sources, and photo- detectors. Despite many efforts to characterize the propagation parameters of these subwavelength 1D plasmonic waveguides, such as Ag nanowires, large discrepancies exist among available reports owing to their sensitivity to the relative weights of co-existing SPP modes and the lack of a method of decoupling these modes and analyzing them separately. In this work, we develop an interference method to distinguish different SPP modes that are simultaneously excited in a Ag nanowire waveguide and measure their propagation parameters separately. By extracting information from the propagation-distance- dependent intensity oscillations of the scattered light from the nanowire tip, the effective refractive indices, propagation lengths, and relative mode weights of co-existing SPP modes supported by the nanowire are derived from a mode interference model. These parameters depend strongly on the nanowire diameter and excitation wavelength. In particular, we demonstrate the possibility of selective excitation of different SPP modes by varying the nanowire diameter. This new mode analysis technique provides unique insights into the develop- ment and optimization of SPP-based applications.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFB1803505)the National Natural Science Foundation of China(Grant Nos.U2001601,62175039,and 61925501)+3 种基金the Science and Technology Project of Guangzhou(Grant No.201904010243)Major Special Projects in Guangdong Province(Grant No.2018B010114002)the Engineering Research Center of Digital Imaging and Display,Ministry of Education,Soochow University(Grant No.SDGC2133)the Program for Guangdong Introducing Innovative and Enterpreneurial Teams.
文摘In this paper,a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal(MIM)waveguide.According to the effective refractive index modulation caused by different waveguide widths in a period,a reflection channel with a large bandwidth is firstly achieved.Besides,the Mach-Zehnder interference(MZI)effect arises by shifting the gratings away from the waveguide center.Owing to different optical paths with unequal indices on both sides of the grating,a narrow MZI band gap will be obtained.It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other,and their wavelengths can be manipulated by the period and the grating length,respectively.Additionally,we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period.The performances are investigated by finite-difference time-domain(FDTD)simulations.In the index range of 1.33–1.36,the maximum sensitivity for the structure is as high as 1500 nm/RIU,and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.