Diffractive optical elements（DOEs） with spectrum separation and beam concentration（SSBC） functions have important applications in solar cell systems. With the SSBC DOEs, the sunlight radiation is divided into seve...Diffractive optical elements（DOEs） with spectrum separation and beam concentration（SSBC） functions have important applications in solar cell systems. With the SSBC DOEs, the sunlight radiation is divided into several wave bands so as to be effectively absorbed by photovoltaic materials with different band gaps. A new method is proposed for designing high-efficiency SSBC DOEs, which is physically simple, numerically fast, and universally applicable. The SSBC DOEs are designed by the new design method, and their performances are analyzed by the Fresnel diffraction integral method.The new design method takes two advantages over the previous design method. Firstly, the optical focusing efficiency is heightened by up to 10%. Secondly, focal positions of all the designed wavelengths can be designated arbitrarily and independently. It is believed that the designed SSBC DOEs should have practical applications to solar cell systems.展开更多
In the Fresnel transform domain, an effective improvement to the conventional iterative algorithm for designing the diffractive optical elements (DOEs) used for spatial beam shaping has been proposed. The algorithm ca...In the Fresnel transform domain, an effective improvement to the conventional iterative algorithm for designing the diffractive optical elements (DOEs) used for spatial beam shaping has been proposed. The algorithm can successfully achieve to design DOEs for beam shaping. Compared with conventional algorithm, this algorithm can provide faster convergence, more powerful ability to overcome local minimum problem and better shaping quality. By computer simulation, the result has shown that the DOEs designed by this algorithm has snch advantages as high uniformity at the main lobe, low profile error and steep edge.展开更多
1 Introduction 1.1 Advantages of DOE 1)High diffraction efficiency; 2)Dispersive; 3)More selectivity of designing parameters; 4)More selectivity of primary materials; 5)Can make components miniature,forming array and ...1 Introduction 1.1 Advantages of DOE 1)High diffraction efficiency; 2)Dispersive; 3)More selectivity of designing parameters; 4)More selectivity of primary materials; 5)Can make components miniature,forming array and integration. 1.2 1.3 megapixel triplet plastic mobile展开更多
In this paper,a novel method is proposed and employed to design a single diffractive optical element（DOE） for implementing spectrum-splitting and beam-concentration（SSBC） functions simultaneously.We develop an opt...In this paper,a novel method is proposed and employed to design a single diffractive optical element（DOE） for implementing spectrum-splitting and beam-concentration（SSBC） functions simultaneously.We develop an optimization algorithm,through which the SSBC DOE can be optimized within an arbitrary thickness range according to the limitations of modern photolithography technology.Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency.It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.展开更多
Based on the facts that multijunction solar cells can increase the efficiency and concentration can reduce the cost dramatically, a special design of parallel multijunction solar cells was presented. The design employ...Based on the facts that multijunction solar cells can increase the efficiency and concentration can reduce the cost dramatically, a special design of parallel multijunction solar cells was presented. The design employed a diffractive optical element （DOE） to split and concentrate the sunlight. A rainbow region and a zero-order diffraction region were generated on the output plane where solar cells with corresponding band gaps were placed. An analytical expression of the light intensity distribution on the output plane of the special DOE was deduced, and the limiting photovoltaic efficiency of such parallel multijunction solar ceils was obtained based on Shockley-Queisser＇s theory. An efficiency exceeding the Shockley--Queisser limit （33%） can be expected using multijunction solar cells consisting of separately fabricated subcells. The results provide an important alternative approach to realize high photovoltaic efficiency without the need for expensive epitaxial technology widely used in tandem solar cells, thus stimulating the research and application of high efficiency and low cost solar cells.展开更多
A spectrum-splitting and beam-concentrating （SSBC） diffractive optical element （DOE） for three-junction pho- tovoltaics （PV） system is designed and fabricated by five-circ/e micro-fabrication. The incident solar...A spectrum-splitting and beam-concentrating （SSBC） diffractive optical element （DOE） for three-junction pho- tovoltaics （PV） system is designed and fabricated by five-circ/e micro-fabrication. The incident solar light is efficiently split into three sub-spectrum ranges and strongly concentrated on the focal plane, which can be di- rectly utilized by suitable spectrum-matching solar cells. The system concentration factor reaches 12x. Moreover, the designed wavelengths （450nm, 550nm and 65Onto） are spatially distributed on the focal plane, in good agree- ment with the theoretical results. The average optical effic/ency of all the cells over the three designed wavelengths is 60.07%. The SSBC DOE with a high concentration factor and a high optical efficiency provides a cost-effective approach to achieve higher PV conversion efficieneies.展开更多
Two improved algorithms are proposed to extend a diffractive optical element （DOE） to work under the broad spec- trum of sunlight. An optimum design has been found for the DOE, with a weighted average optical effici...Two improved algorithms are proposed to extend a diffractive optical element （DOE） to work under the broad spec- trum of sunlight. An optimum design has been found for the DOE, with a weighted average optical efficiency of about 6.8% better than that of the previous design. The optimization of designing high optical efficiency DOEs will pave the way for future designs of high-efficiency, low-cost lateral multijunction solar cells based on such a DOE.展开更多
Demonstrated that analog of diffractive and refractive 3D optics in free space can be developed to manipulate surface waves such as surface plasmon polaritons (SPPs). It has been shown that an air-gap control of a flo...Demonstrated that analog of diffractive and refractive 3D optics in free space can be developed to manipulate surface waves such as surface plasmon polaritons (SPPs). It has been shown that an air-gap control of a floating dielectric block can generate the dynamic phase and amplitude modulation of the SPP transmission coefficient. Unlike conventional bulk optics, the nano-scale surface optics for SPP processing contains several unexpected and interesting features in addition to the physical features described. Dynamic plasmonic information processing on the nano-scale using air-gap control may be an effective mechanism for building a dynamic plasmonic information processing system.展开更多
Diffractive optical elements have a large number of industrial applications, such as beam shaping and optical filtering. Traditionally, these elements modulate the phase of the incoming light or its amplitude, but not...Diffractive optical elements have a large number of industrial applications, such as beam shaping and optical filtering. Traditionally, these elements modulate the phase of the incoming light or its amplitude, but not both. To overcome this limitation, full complex-amplitude modulation diffractive optical elements were developed. Well-established integrated circuit fabrication steps were employed to fabricate the devices with high precision. Using this approach, the new element's optical performances are improved also for near field operations. With this device it is possible to obtain 100% efficient spatial filtering and low noise reconstructed images.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2013CBA01702)the National Natural Science Foundation of China(Grant Nos.11474206,91233202,11374216,and 11404224)+1 种基金the Scientific Research Project of Beijing Education Commission,China(Grant No.KM201310028005)the Scientific Research Base Development Program of the Beijing Municipal Commission of Education and the Beijing Youth Top-Notch Talent Training Plan,China(Grant No.CIT&TCD201504080)
文摘Diffractive optical elements（DOEs） with spectrum separation and beam concentration（SSBC） functions have important applications in solar cell systems. With the SSBC DOEs, the sunlight radiation is divided into several wave bands so as to be effectively absorbed by photovoltaic materials with different band gaps. A new method is proposed for designing high-efficiency SSBC DOEs, which is physically simple, numerically fast, and universally applicable. The SSBC DOEs are designed by the new design method, and their performances are analyzed by the Fresnel diffraction integral method.The new design method takes two advantages over the previous design method. Firstly, the optical focusing efficiency is heightened by up to 10%. Secondly, focal positions of all the designed wavelengths can be designated arbitrarily and independently. It is believed that the designed SSBC DOEs should have practical applications to solar cell systems.
文摘In the Fresnel transform domain, an effective improvement to the conventional iterative algorithm for designing the diffractive optical elements (DOEs) used for spatial beam shaping has been proposed. The algorithm can successfully achieve to design DOEs for beam shaping. Compared with conventional algorithm, this algorithm can provide faster convergence, more powerful ability to overcome local minimum problem and better shaping quality. By computer simulation, the result has shown that the DOEs designed by this algorithm has snch advantages as high uniformity at the main lobe, low profile error and steep edge.
文摘1 Introduction 1.1 Advantages of DOE 1)High diffraction efficiency; 2)Dispersive; 3)More selectivity of designing parameters; 4)More selectivity of primary materials; 5)Can make components miniature,forming array and integration. 1.2 1.3 megapixel triplet plastic mobile
基金Project supported by the National Basic Research Program of China (Grant No. 2011CB301801)the National Natural Science Foundation of China (GrantNos. 91233202,10904099,11204188,61205097,and 11174211)
文摘In this paper,a novel method is proposed and employed to design a single diffractive optical element（DOE） for implementing spectrum-splitting and beam-concentration（SSBC） functions simultaneously.We develop an optimization algorithm,through which the SSBC DOE can be optimized within an arbitrary thickness range according to the limitations of modern photolithography technology.Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency.It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.91233202,21173260,and 51072221)the National Basic Research Program of China(Grant No.2012CB932903)
文摘Based on the facts that multijunction solar cells can increase the efficiency and concentration can reduce the cost dramatically, a special design of parallel multijunction solar cells was presented. The design employed a diffractive optical element （DOE） to split and concentrate the sunlight. A rainbow region and a zero-order diffraction region were generated on the output plane where solar cells with corresponding band gaps were placed. An analytical expression of the light intensity distribution on the output plane of the special DOE was deduced, and the limiting photovoltaic efficiency of such parallel multijunction solar ceils was obtained based on Shockley-Queisser＇s theory. An efficiency exceeding the Shockley--Queisser limit （33%） can be expected using multijunction solar cells consisting of separately fabricated subcells. The results provide an important alternative approach to realize high photovoltaic efficiency without the need for expensive epitaxial technology widely used in tandem solar cells, thus stimulating the research and application of high efficiency and low cost solar cells.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91233202,91433205 and 51421002the Chinese Academy of Sciences
文摘A spectrum-splitting and beam-concentrating （SSBC） diffractive optical element （DOE） for three-junction pho- tovoltaics （PV） system is designed and fabricated by five-circ/e micro-fabrication. The incident solar light is efficiently split into three sub-spectrum ranges and strongly concentrated on the focal plane, which can be di- rectly utilized by suitable spectrum-matching solar cells. The system concentration factor reaches 12x. Moreover, the designed wavelengths （450nm, 550nm and 65Onto） are spatially distributed on the focal plane, in good agree- ment with the theoretical results. The average optical effic/ency of all the cells over the three designed wavelengths is 60.07%. The SSBC DOE with a high concentration factor and a high optical efficiency provides a cost-effective approach to achieve higher PV conversion efficieneies.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.91233202,21173260,and 51072221)the National Basic Research Program of China(Grant No.2012CB932903
文摘Two improved algorithms are proposed to extend a diffractive optical element （DOE） to work under the broad spec- trum of sunlight. An optimum design has been found for the DOE, with a weighted average optical efficiency of about 6.8% better than that of the previous design. The optimization of designing high optical efficiency DOEs will pave the way for future designs of high-efficiency, low-cost lateral multijunction solar cells based on such a DOE.
文摘Demonstrated that analog of diffractive and refractive 3D optics in free space can be developed to manipulate surface waves such as surface plasmon polaritons (SPPs). It has been shown that an air-gap control of a floating dielectric block can generate the dynamic phase and amplitude modulation of the SPP transmission coefficient. Unlike conventional bulk optics, the nano-scale surface optics for SPP processing contains several unexpected and interesting features in addition to the physical features described. Dynamic plasmonic information processing on the nano-scale using air-gap control may be an effective mechanism for building a dynamic plasmonic information processing system.
文摘Diffractive optical elements have a large number of industrial applications, such as beam shaping and optical filtering. Traditionally, these elements modulate the phase of the incoming light or its amplitude, but not both. To overcome this limitation, full complex-amplitude modulation diffractive optical elements were developed. Well-established integrated circuit fabrication steps were employed to fabricate the devices with high precision. Using this approach, the new element's optical performances are improved also for near field operations. With this device it is possible to obtain 100% efficient spatial filtering and low noise reconstructed images.
