In order to solve a problem of oil on-line monitoring,this instrument adopts a principium of self-focus lens of Gradient index fiber(GRIN Len)to design optics system and magnetic circuit.For the magnetic circuit,the m...In order to solve a problem of oil on-line monitoring,this instrument adopts a principium of self-focus lens of Gradient index fiber(GRIN Len)to design optics system and magnetic circuit.For the magnetic circuit,the monitor can catch particle wear debris in oil.And for the optics circuit.GRIN Len can transfer image of debris to apparatus of gather image,e.g,CCD and camera.And the image of debris is transferred to computer for analyzing seize and physiognomy of debris.The character of the monitor is of micro weight,micro volume and curve imaging.And it is directly pluged into oil to catch image of wear particles.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
Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that ex...Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that extends many optical imaging modalities like harmonic laser scanned imaging with micro endoscopic in vivo capabilities as needed in research and diagnostics. These micro endoscopic imaging variants however rely on the light scattering capability of the underlying tissue. Further complications arise from an increased number of optical interfaces and the overall optical performance of a GRIN rod. We have therefore performed a quantitative comparison of the back-scattered second harmonic generation (SHG) signal intensity generated in skin and low-scattering muscle tissue, both obtained with a standard two photon laser scanning microscope (LSM) and a GRIN lens based LSM. We report that the GRIN lens based system sees approximately 1/4 of the net two photon signal detected by the standard LSM. We expect that this value can be generalized to other LSM techniques enhanced by GRIN technology and encourage its use in experimental situations with standard LSM signal to noise ratios of four or higher.展开更多
Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are id...Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.展开更多
In this paper a gradient index media plate is described. The media plate has some properties similar to the Schmidt aspherical corrective plate. In the catadioptiric system,Duncan T. Moors has studied a axial gradien...In this paper a gradient index media plate is described. The media plate has some properties similar to the Schmidt aspherical corrective plate. In the catadioptiric system,Duncan T. Moors has studied a axial gradient index corrective plate and gave a better result. His plate,in fact,is a zero power plate with two Spherical surfaces of different radius of curvature. However ,my plate is a parallel plate designed forth a shallow radial gradient index media. The spherical aberration of the gradient index corrector with parallel plane ed eliminate the spherical aberration of the spherical primary mirror in the catadioptiric system. In this paper the aberrational correction is analyzed. In the conventional optical systems,this gradient index plate is used to provide the precorrectional quantity of the spherical aberration of the optical lee systems. The refractive index in such a media in the lens systems is given in the same way.展开更多
Integrated photonics is expected to play an increasingly important role in optical communications,imaging,computing and sensing with the promise for significant reduction in the cost and weight of these systems.Future...Integrated photonics is expected to play an increasingly important role in optical communications,imaging,computing and sensing with the promise for significant reduction in the cost and weight of these systems.Future advancement of this technology is critically dependent on an ability to develop compact and reliable optical components and facilitate their integration on a common substrate.Here we reveal,with the utility of the emerging transformation optics technique,that functional components composed of planar gradient index materials can be designed and readily integrated into photonic circuits.The unprecedented design flexibility of transformation optics allows for the creation of a number of novel devices,such as a light source collimator,waveguide adapters and a waveguide crossing,which have broad applications in integrated photonic chips and are compatible with current fabrication technology.Using the finite-difference time-domain method,we perform full-wave numerical simulations to demonstrate their superior optical performance and efficient integration with other components in an on-chip photonic system.These components only require spatially-varying dielectric materials with no magnetic properties,facilitating low-loss,broadband operation in an integrated photonic environment.展开更多
We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be...We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging.展开更多
We demonstrate that asymmetric acoustic wave transmission in a waveguide can be achieved via gradient index metamaterials(GIMs). We theoretically prove that the acoustic wave can be efficiently converted to surface wa...We demonstrate that asymmetric acoustic wave transmission in a waveguide can be achieved via gradient index metamaterials(GIMs). We theoretically prove that the acoustic wave can be efficiently converted to surface waves(SWs) via GIMs. The GIMs in a waveguide can allow the transmission of acoustic waves in one direction but block them in the other direction. This theory is validated by experiments. Our findings may provide new applications in various scenarios such as high-efficiency acoustic couplers and noise control.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
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
In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. F...In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. Firstly, the model of the GRIN fibre probe is presented, which is consisted of a single mode fibre （SMF）, a no-core fibre （NCF）, a GRIN fibre lens and an air path. Then, the software GLAD is adopted to numerically investigate how the lengths of the NCF and the GRIN fibre lens influence the performance of the Gaussian beam focusing through the GRIN fibre probe. The simulation results are well consistent with the experimental ones, showing that the GLAD based numerical simulation technique is an intuitive and effective tool for the verification of the properties of the light propagation. In this paper, we find that on the conditions of a constant GRIN fibre lens length of 0.1 mm and an NCF length of 0.36 mm, the working distance of the probe will be 0.75 mm and the focus spot size is 32 μm.展开更多
Gradient-index rod lens (GRIN-lens) whose pitch is ordinary value with bevel ferrule coupling system is analyzed, an equivalent method which can be used to analyze this system is put forward, and a general formula for...Gradient-index rod lens (GRIN-lens) whose pitch is ordinary value with bevel ferrule coupling system is analyzed, an equivalent method which can be used to analyze this system is put forward, and a general formula for determining the coupling loss with axes mismatch, radial mismatch, and angular mismatch is derived by use of the Gaussian field approximation and mode-field coupling theory. The experimental results are in good agreement with the theory prediction. It indicates that these formulas are suitable to analyze the gradient-index rod lens coupling system with pigtail fiber.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
Under the background of the 'Southwardly Development' of Guangzhou City,this paper chooses Panyu District as the research object and uses the 2005 land use data to quantitatively analyze the landscape layout a...Under the background of the 'Southwardly Development' of Guangzhou City,this paper chooses Panyu District as the research object and uses the 2005 land use data to quantitatively analyze the landscape layout and its change in the study area based on the support of GIS and Fragstats through combining landscape index and gradient analysis.The results show that it is feasible to show urbanization and the change of the spatial pattern of urban landscape through utilizing gradient analysis and landscape index.Over the course of 'Southwardly Development',the urbanization level of Panyu District has been enhanced unceasingly.And the landscape spatial patterns of different land uses and their variation characteristics are obviously different.展开更多
文摘In order to solve a problem of oil on-line monitoring,this instrument adopts a principium of self-focus lens of Gradient index fiber(GRIN Len)to design optics system and magnetic circuit.For the magnetic circuit,the monitor can catch particle wear debris in oil.And for the optics circuit.GRIN Len can transfer image of debris to apparatus of gather image,e.g,CCD and camera.And the image of debris is transferred to computer for analyzing seize and physiognomy of debris.The character of the monitor is of micro weight,micro volume and curve imaging.And it is directly pluged into oil to catch image of wear particles.
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Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that extends many optical imaging modalities like harmonic laser scanned imaging with micro endoscopic in vivo capabilities as needed in research and diagnostics. These micro endoscopic imaging variants however rely on the light scattering capability of the underlying tissue. Further complications arise from an increased number of optical interfaces and the overall optical performance of a GRIN rod. We have therefore performed a quantitative comparison of the back-scattered second harmonic generation (SHG) signal intensity generated in skin and low-scattering muscle tissue, both obtained with a standard two photon laser scanning microscope (LSM) and a GRIN lens based LSM. We report that the GRIN lens based system sees approximately 1/4 of the net two photon signal detected by the standard LSM. We expect that this value can be generalized to other LSM techniques enhanced by GRIN technology and encourage its use in experimental situations with standard LSM signal to noise ratios of four or higher.
基金financial support by the National Key Research and Development Program of China(No.2023YFB4605400)the National Natural Science Foundation of China(No.12472152)the Department of Science and Technology of Guangdong Province(No.2019QN01Z438)。
文摘Gradient refractive index(GRIN)metalenses are increasingly valued in high-frequency communication due to their exceptional radiation performance.Ceramics with high dielectric constants and low dielectric losses are ideal candidates for GRIN metalenses.Digital light processing(DLP)3D printing provides a feasible and efficient approach for manufacturing ceramic GRIN metalenses.However,the scattering of ultraviolet(UV)light by ceramic particles in the slurry reduces the printing accuracy of DLP technology,making it difficult to achieve the intricate structural features required for GRIN metalenses in high-frequency communication.In this work,we propose an approach to improve printing accuracy by optimizing the ceramic slurry composition and implementing a dimensional compensation design strategy.Utilizing geometric optics and the S-parameter inversion method,we design a GRIN metalens consisting of two distinct types of subwavelength unit cells(Y-shaped and circular hole geometries)with a minimum feature size of 160μm.Through a refined slurry formulation and precise design parameter compensation,high-fidelity ceramic GRIN metalenses are successfully fabricated.The fabricated metalens exhibits a maximum gain enhancement of 18.4 dBi and a deflection angle of±30°over a bandwidth of 37.84% in the W-band(75-110 GHz).The highly directional far-field beam radiation and efficient beam steering capabilities highlight the potential of ceramic GRIN metalenses for applications in satellite communications,radar systems,and other high-frequency technologies.
文摘In this paper a gradient index media plate is described. The media plate has some properties similar to the Schmidt aspherical corrective plate. In the catadioptiric system,Duncan T. Moors has studied a axial gradient index corrective plate and gave a better result. His plate,in fact,is a zero power plate with two Spherical surfaces of different radius of curvature. However ,my plate is a parallel plate designed forth a shallow radial gradient index media. The spherical aberration of the gradient index corrector with parallel plane ed eliminate the spherical aberration of the spherical primary mirror in the catadioptiric system. In this paper the aberrational correction is analyzed. In the conventional optical systems,this gradient index plate is used to provide the precorrectional quantity of the spherical aberration of the optical lee systems. The refractive index in such a media in the lens systems is given in the same way.
基金Partial support for this work was provided by the NSF MRSEC(Grant No.DMR-0820404).We thank Peter Sieber for his assistance with some of the figure visualizations.
文摘Integrated photonics is expected to play an increasingly important role in optical communications,imaging,computing and sensing with the promise for significant reduction in the cost and weight of these systems.Future advancement of this technology is critically dependent on an ability to develop compact and reliable optical components and facilitate their integration on a common substrate.Here we reveal,with the utility of the emerging transformation optics technique,that functional components composed of planar gradient index materials can be designed and readily integrated into photonic circuits.The unprecedented design flexibility of transformation optics allows for the creation of a number of novel devices,such as a light source collimator,waveguide adapters and a waveguide crossing,which have broad applications in integrated photonic chips and are compatible with current fabrication technology.Using the finite-difference time-domain method,we perform full-wave numerical simulations to demonstrate their superior optical performance and efficient integration with other components in an on-chip photonic system.These components only require spatially-varying dielectric materials with no magnetic properties,facilitating low-loss,broadband operation in an integrated photonic environment.
基金supported by the National Basic Research Program of China(Grant No.2012CB921504)the National Natural Science Foundation of China(Grant Nos.11574148,11474162,1274171,11674172,and 11674175)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant Nos.20110091120040 and 20120091110001)
文摘We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging.
基金supported by the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700202,and 2017YFA0700203)the National Natural Science Foundation of China(61631007,61571117,61138001,61371035,61722106,61731010 and 11227904)the 111Project(111-2-05)
文摘We demonstrate that asymmetric acoustic wave transmission in a waveguide can be achieved via gradient index metamaterials(GIMs). We theoretically prove that the acoustic wave can be efficiently converted to surface waves(SWs) via GIMs. The GIMs in a waveguide can allow the transmission of acoustic waves in one direction but block them in the other direction. This theory is validated by experiments. Our findings may provide new applications in various scenarios such as high-efficiency acoustic couplers and noise control.
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 International Cooperation Project of Shanghai Science and Technology Committee,China(Grant No.09530708700)
文摘In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. Firstly, the model of the GRIN fibre probe is presented, which is consisted of a single mode fibre （SMF）, a no-core fibre （NCF）, a GRIN fibre lens and an air path. Then, the software GLAD is adopted to numerically investigate how the lengths of the NCF and the GRIN fibre lens influence the performance of the Gaussian beam focusing through the GRIN fibre probe. The simulation results are well consistent with the experimental ones, showing that the GLAD based numerical simulation technique is an intuitive and effective tool for the verification of the properties of the light propagation. In this paper, we find that on the conditions of a constant GRIN fibre lens length of 0.1 mm and an NCF length of 0.36 mm, the working distance of the probe will be 0.75 mm and the focus spot size is 32 μm.
文摘Gradient-index rod lens (GRIN-lens) whose pitch is ordinary value with bevel ferrule coupling system is analyzed, an equivalent method which can be used to analyze this system is put forward, and a general formula for determining the coupling loss with axes mismatch, radial mismatch, and angular mismatch is derived by use of the Gaussian field approximation and mode-field coupling theory. The experimental results are in good agreement with the theory prediction. It indicates that these formulas are suitable to analyze the gradient-index rod lens coupling system with pigtail fiber.
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.
文摘Under the background of the 'Southwardly Development' of Guangzhou City,this paper chooses Panyu District as the research object and uses the 2005 land use data to quantitatively analyze the landscape layout and its change in the study area based on the support of GIS and Fragstats through combining landscape index and gradient analysis.The results show that it is feasible to show urbanization and the change of the spatial pattern of urban landscape through utilizing gradient analysis and landscape index.Over the course of 'Southwardly Development',the urbanization level of Panyu District has been enhanced unceasingly.And the landscape spatial patterns of different land uses and their variation characteristics are obviously different.
