The gel rod, partially polymerized DAP (diallyl phthalate), is immersed in MMA (methyl methacrylate) solution, followed by heat-treatment to yield the GRIN (gradient ref- ractive index) rod. A three-stage mechanism of...The gel rod, partially polymerized DAP (diallyl phthalate), is immersed in MMA (methyl methacrylate) solution, followed by heat-treatment to yield the GRIN (gradient ref- ractive index) rod. A three-stage mechanism of diffusion-copolymerization process is propo- sed, giving an interpretation to the formation of cracks that are brought about in large-dia- meter GRIN rods.展开更多
We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.Th...We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.The trajectory of an acoustic wave within the system is derived by employing the theory of geometric acoustics,and the validity of the theoretical descriptions is verified numerically by using the finite element method simulation.The results show that by tailoring the distribution function of the refractive index,the proposed system can yield a tunable manipulation of acoustic waves,such as acoustic bending,trapping,and absorbing.展开更多
In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl...In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.展开更多
Propagation of electromagnetic wave (EW) through multilayer structure consisting anisotropic layers with gradient refractive index material is studied theoretically. Analytical solution for linear dependence of refrac...Propagation of electromagnetic wave (EW) through multilayer structure consisting anisotropic layers with gradient refractive index material is studied theoretically. Analytical solution for linear dependence of refractive index profile is examined. The structure consist the forbidden gaps, which are sensitive to parameters of refractive index profile.展开更多
It is shown that aplanatic lens with a radial gradient of refraction index is simultaneously a telescopic lens, notably not only for an axial beam, but also for an off axis parallel beam. Consideration is carried out ...It is shown that aplanatic lens with a radial gradient of refraction index is simultaneously a telescopic lens, notably not only for an axial beam, but also for an off axis parallel beam. Consideration is carried out by an algebraic way on the basis of regularities of ray paths. It is also shown that aplanatic and telescopic properties of the lens are independent of the refracting surface shapes. Various versions of lens performance are shown below.展开更多
Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)...Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.展开更多
The long period fiber grating （LPFG） is widely used as a sensor due to its high sensitivity and resolution. However, the broad bandwidth of the attenuation bands formed by the mode coupling between the fundamental c...The long period fiber grating （LPFG） is widely used as a sensor due to its high sensitivity and resolution. However, the broad bandwidth of the attenuation bands formed by the mode coupling between the fundamental core mode and the cladding modes constitutes a difficulty when the device is used as a conventional sensor. To overcome this limitation, a Michelson interferometer-type sensor configuration has been developed, using an LPFG grating pair formed by coating a mirror at the distal end of the LPFG. This sensor configuration is more convenient to use and is able to overcome the limitations of the single LPFG based sensor as the shifts in the attenuation bands being more easily detectable due to the formation of the sharp spectral fringe pattern in the LPFG based Michelson interferometer. In this work, I studied the LPFG based Michelson interferometer as the refractive index sensor and discussed the sensitivity enhancement of the LPFG based Michelson interferometer as a refractive index sensor by employing higher order cladding modes and by reducing the cladding radius. The results demonstrated the HE17 mode with a cladding radius of 62.5 μm, in the range of surrounding refractive index （SRI） of 1 - 1.45, and its resonant peak showed a wavelength shift of 26.99nm/RIU. When the cladding region was further reduced to 24μm, the resonant peak showed a wavelength shift of 569.88 nm/RIU, resulting in a sensitivity enhancement of nearly 21 times. However, as the cladding region was etched further, then the HE17 order cladding mode and higher mode would be cut off. Therefore, the implementation of high sensitivity for SRI sensing with the reduced cladding in the LPFG based Michelson interferometer is dependent on the proper combination of the cladding radius and cladding mode order.展开更多
An approach to the simultaneous optical ring resonators is proposed measurement of refractive-index （RI） and theoretically demonstrated. With and temperature changes using a liquid-core silica ring resonator as an e...An approach to the simultaneous optical ring resonators is proposed measurement of refractive-index （RI） and theoretically demonstrated. With and temperature changes using a liquid-core silica ring resonator as an example, two different-order whispering gallery modes （WGMs） might differ in not only RI but also temperature sensitivities. Thus, a second-order sensing matrix should be defined based on these WGMs to determine RI and temperature changes simultaneously. The analysis shows that the RI and temperature detection limits can be achieved on the order of 10.7 RI unit and 10-3 K at a wavelength of approximately 780 nm.展开更多
基于湍流散射理论,运用边界层风廓线雷达(WPR)联合RASS(Radio Acoustic Sounding System),GPS/PWV(Global Position System/Precipitable Water Vapor)进行全遥感系统的大气比湿廓线反演试验,并对影响因子进行分析。利用2011年8—9月云...基于湍流散射理论,运用边界层风廓线雷达(WPR)联合RASS(Radio Acoustic Sounding System),GPS/PWV(Global Position System/Precipitable Water Vapor)进行全遥感系统的大气比湿廓线反演试验,并对影响因子进行分析。利用2011年8—9月云南大理综合探测试验数据的反演结果与探空数据进行比较分析,结果表明:WPR联合探空的温度廓线和起始边界比湿(q_0)反演大气比湿廓线,与探空大气比湿廓线相比具有相同的变化趋势,标准差为0.84 g·kg^(-1),误差随高度增加呈递增趋势;WPR联合RASS,GPS/PWV数据反演大气比湿廓线,与探空大气比湿廓线的标准差为0.85 g·kg^(-1)。参加反演的数据中,折射指数结构常数C_n^2与谱宽σ_(turb)~2对反演影响最大,反演算法中大气折射指数梯度M符号的判断对反演精度也有较大影响。展开更多
文摘The gel rod, partially polymerized DAP (diallyl phthalate), is immersed in MMA (methyl methacrylate) solution, followed by heat-treatment to yield the GRIN (gradient ref- ractive index) rod. A three-stage mechanism of diffusion-copolymerization process is propo- sed, giving an interpretation to the formation of cracks that are brought about in large-dia- meter GRIN rods.
基金supported by the National Basic Research Program of China(Grant Nos.2010CB327803 and 2012CB921504)the National Natural Science Foundation of China(Grant Nos.11174138,11174139,11222442,81127901,and 11274168)+1 种基金NCET-12-0254the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘We present a detailed theoretical description of wave propagation in an acoustic gradient-index system with cylindrical symmetry and demonstrate its potential to numerically control acoustic waves in different ways.The trajectory of an acoustic wave within the system is derived by employing the theory of geometric acoustics,and the validity of the theoretical descriptions is verified numerically by using the finite element method simulation.The results show that by tailoring the distribution function of the refractive index,the proposed system can yield a tunable manipulation of acoustic waves,such as acoustic bending,trapping,and absorbing.
文摘In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.
文摘Propagation of electromagnetic wave (EW) through multilayer structure consisting anisotropic layers with gradient refractive index material is studied theoretically. Analytical solution for linear dependence of refractive index profile is examined. The structure consist the forbidden gaps, which are sensitive to parameters of refractive index profile.
文摘It is shown that aplanatic lens with a radial gradient of refraction index is simultaneously a telescopic lens, notably not only for an axial beam, but also for an off axis parallel beam. Consideration is carried out by an algebraic way on the basis of regularities of ray paths. It is also shown that aplanatic and telescopic properties of the lens are independent of the refracting surface shapes. Various versions of lens performance are shown below.
基金Project supported by the National Natural Science Foundation of China(Grant No.12175107)the Qing Lan Project of Jiangsu Province+2 种基金the Hua Li Talents Program of Nanjing University of PostsTelecommunications,Natural Science Foundation of Nanjing Vocational University of Industry Technology(Grant No.YK22-02-08)the Fund from the Research Center of Industrial Perception and Intelligent Manufacturing Equipment Engineering of Jiangsu Province,China(Grant No.ZK21-05-09)。
文摘Surface polaritons,as surface electromagnetic waves propagating along the surface of a medium,have played a crucial role in enhancing photonic spin Hall effect(PSHE)and developing highly sensitive refractive index(RI)sensors.Among them,the traditional surface plasmon polariton(SPP)based on noble metals limits its application beyond the near-infrared(IR)regime due to the large negative permittivity and optical losses.In this contribution,we theoretically proposed a highly sensitive PSHE sensor with the structure of Ge prism-SiC-Si:InAs-sensing medium,by taking advantage of the hybrid surface plasmon phonon polariton(SPPhP)in mid-IR regime.Here,heavily Si-doped InAs(Si:InAs)and SiC excite the SPP and surface phonon polariton(SPhP),and the hybrid SPPhP is realized in this system.More importantly,the designed PSHE sensor based on this SPPhP mechanism achieves the multi-stage RI measurements from 1.00025-1.00225 to 1.70025-1.70225,and the maximal intensity sensitivity and angle sensitivity can be up to 9.4×10^(4)μm/RIU and245°/RIU,respectively.These findings provide a new pathway for the enhancement of PSHE in mid-IR regime,and offer new opportunities to develop highly sensitive RI sensors in multi-scenario applications,such as harmful gas monitoring and biosensing.
文摘The long period fiber grating （LPFG） is widely used as a sensor due to its high sensitivity and resolution. However, the broad bandwidth of the attenuation bands formed by the mode coupling between the fundamental core mode and the cladding modes constitutes a difficulty when the device is used as a conventional sensor. To overcome this limitation, a Michelson interferometer-type sensor configuration has been developed, using an LPFG grating pair formed by coating a mirror at the distal end of the LPFG. This sensor configuration is more convenient to use and is able to overcome the limitations of the single LPFG based sensor as the shifts in the attenuation bands being more easily detectable due to the formation of the sharp spectral fringe pattern in the LPFG based Michelson interferometer. In this work, I studied the LPFG based Michelson interferometer as the refractive index sensor and discussed the sensitivity enhancement of the LPFG based Michelson interferometer as a refractive index sensor by employing higher order cladding modes and by reducing the cladding radius. The results demonstrated the HE17 mode with a cladding radius of 62.5 μm, in the range of surrounding refractive index （SRI） of 1 - 1.45, and its resonant peak showed a wavelength shift of 26.99nm/RIU. When the cladding region was further reduced to 24μm, the resonant peak showed a wavelength shift of 569.88 nm/RIU, resulting in a sensitivity enhancement of nearly 21 times. However, as the cladding region was etched further, then the HE17 order cladding mode and higher mode would be cut off. Therefore, the implementation of high sensitivity for SRI sensing with the reduced cladding in the LPFG based Michelson interferometer is dependent on the proper combination of the cladding radius and cladding mode order.
基金supported by the National "973" Program of China (No. 2011CB013000)the National Natural Science Foundation of China (Nos. 90923039and 51025521)
文摘An approach to the simultaneous optical ring resonators is proposed measurement of refractive-index （RI） and theoretically demonstrated. With and temperature changes using a liquid-core silica ring resonator as an example, two different-order whispering gallery modes （WGMs） might differ in not only RI but also temperature sensitivities. Thus, a second-order sensing matrix should be defined based on these WGMs to determine RI and temperature changes simultaneously. The analysis shows that the RI and temperature detection limits can be achieved on the order of 10.7 RI unit and 10-3 K at a wavelength of approximately 780 nm.
文摘基于湍流散射理论,运用边界层风廓线雷达(WPR)联合RASS(Radio Acoustic Sounding System),GPS/PWV(Global Position System/Precipitable Water Vapor)进行全遥感系统的大气比湿廓线反演试验,并对影响因子进行分析。利用2011年8—9月云南大理综合探测试验数据的反演结果与探空数据进行比较分析,结果表明:WPR联合探空的温度廓线和起始边界比湿(q_0)反演大气比湿廓线,与探空大气比湿廓线相比具有相同的变化趋势,标准差为0.84 g·kg^(-1),误差随高度增加呈递增趋势;WPR联合RASS,GPS/PWV数据反演大气比湿廓线,与探空大气比湿廓线的标准差为0.85 g·kg^(-1)。参加反演的数据中,折射指数结构常数C_n^2与谱宽σ_(turb)~2对反演影响最大,反演算法中大气折射指数梯度M符号的判断对反演精度也有较大影响。
