In this paper, an ultrathin metalens has been proposed based on a holographic metasurface that consists of elongated apertures in 40 nm gold film, which exhibit intriguing properties such as on-and off-axis focusing a...In this paper, an ultrathin metalens has been proposed based on a holographic metasurface that consists of elongated apertures in 40 nm gold film, which exhibit intriguing properties such as on-and off-axis focusing and also can concentrate light into multiple, discrete spots for circularly polarized incident lights. First, the spatial transmission phase distributions of the designed metalens with arbitrary focusing can be obtained by computergenerated holography. Then, the discrete phase distributions can be continuously encoded by subwavelength nanoapertures with spatially varying orientations in gold film. The simulation results show that our designed metalens can work efficiently for different types of focusing. Finally, our metasurface shows superior broadband characteristics between 670 and 810 nm, and the corresponding focal lengths of the designed lenses also can be efficiently modulated with the incident lights at different wavelengths.展开更多
A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced, the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach. A kind...A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced, the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach. A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented. In addition, a two-time coating method is used to improve the numerical apertures of the compound lenses. Furthermore, the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.展开更多
A method based on the diffraction theory for estimating the three-dimensional (3D) focusing performance of the compound refractive X-ray lenses is presented in this paper. As a special application, the 3D X-ray intens...A method based on the diffraction theory for estimating the three-dimensional (3D) focusing performance of the compound refractive X-ray lenses is presented in this paper. As a special application, the 3D X-ray intensity distribution near the focus is derived for a plano-concave compound refractive X-ray lens. Moreover, the computer codes are developed and some results of 3D focusing performance for a compound refractive X-ray lens with Si material are shown and discussed.展开更多
It is important to predict the intensity distribution in focusing plane for designing the X-ray compound refractive lenses. On the basis of analyzing the structure of X-ray compound lenses and comparing it with Praunh...It is important to predict the intensity distribution in focusing plane for designing the X-ray compound refractive lenses. On the basis of analyzing the structure of X-ray compound lenses and comparing it with Praunhofer diffraction system, it is concluded that the X-ray focusing system can be regarded as a kind of Praunhofer diffraction system. Therefore, a method based on Fourier spectrum analysis is presented to predict the intensity distribution in the focusing plane for the X-ray lenses. A brief analysis on the relationship between the parameters of X-ray lenses and their focusing performance is also given in this paper.展开更多
A double-zone aspheric diffractive intraocular lens （IOL） was designed and manufactured aiming to regain a continuous range of clear vision for pseudophakic presbyopia. After obtaining the IOL structure parameters t...A double-zone aspheric diffractive intraocular lens （IOL） was designed and manufactured aiming to regain a continuous range of clear vision for pseudophakic presbyopia. After obtaining the IOL structure parameters through optimization based on an aphakic model eye, its imaging performances were analyzed in the model eye. The modulation transfer function at 50 cycles/mm remained above 0.29 within ±5° field of view for object distance ranging from 6 to 0.66 m. In addition, the imaging qualities are robust for pupil changes, polychromatic light, and different corneal asphericities. The manufactured IOL exhibits the abilitv to extend depth of focus.展开更多
We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture （NA） lens. Different and relevant states of polarization as well as field ...We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture （NA） lens. Different and relevant states of polarization as well as field distributions can be created by the simple turning of a λ/2 retardation wave plate placed in the excitation path of a micro- scope. The realization of such a versatile excitation source can provide an essential tool for nanotechnology investigations and biomedical experiments.展开更多
基金financial supports for this work from the Fundamental Research Funds for the Central Universities (2015HGCH0010)the Foundation of Hefei University of Technology of China (HFUT. 407-037026)
文摘In this paper, an ultrathin metalens has been proposed based on a holographic metasurface that consists of elongated apertures in 40 nm gold film, which exhibit intriguing properties such as on-and off-axis focusing and also can concentrate light into multiple, discrete spots for circularly polarized incident lights. First, the spatial transmission phase distributions of the designed metalens with arbitrary focusing can be obtained by computergenerated holography. Then, the discrete phase distributions can be continuously encoded by subwavelength nanoapertures with spatially varying orientations in gold film. The simulation results show that our designed metalens can work efficiently for different types of focusing. Finally, our metasurface shows superior broadband characteristics between 670 and 810 nm, and the corresponding focal lengths of the designed lenses also can be efficiently modulated with the incident lights at different wavelengths.
基金This work was supported by the Research Foundation from Ministry of Education of China （No. 204060）, and the Natural Science Foundation of Zhejiang Province （No. Y104203）.
文摘A method based on Fourier spectrum analysis for predicting the performances of the X-ray compound lenses is briefly introduced, the theoretical result obtained is the same as that of Fresnel-Kirchhoff approach. A kind of technique named moulding is developed for fabricating the one-dimensional (1D) compound X-ray lens with Al material and the fabrication process is presented. In addition, a two-time coating method is used to improve the numerical apertures of the compound lenses. Furthermore, the focusing performance of the Al compound X-ray lens under the high energy X-rays is measured.
基金This work was supported by the National Natural Science Foundation of China (No. 10174079)the fund for the qualified researchers in the Zhejiang University of Technology, P. R. China.
文摘A method based on the diffraction theory for estimating the three-dimensional (3D) focusing performance of the compound refractive X-ray lenses is presented in this paper. As a special application, the 3D X-ray intensity distribution near the focus is derived for a plano-concave compound refractive X-ray lens. Moreover, the computer codes are developed and some results of 3D focusing performance for a compound refractive X-ray lens with Si material are shown and discussed.
基金This work was performed with the support from the National Natural Science Foundation of China (No. 10174079) the fund for the qualified researchers in Zhejiang University of Technology, P. R. China.
文摘It is important to predict the intensity distribution in focusing plane for designing the X-ray compound refractive lenses. On the basis of analyzing the structure of X-ray compound lenses and comparing it with Praunhofer diffraction system, it is concluded that the X-ray focusing system can be regarded as a kind of Praunhofer diffraction system. Therefore, a method based on Fourier spectrum analysis is presented to predict the intensity distribution in the focusing plane for the X-ray lenses. A brief analysis on the relationship between the parameters of X-ray lenses and their focusing performance is also given in this paper.
基金supported by the National Natural Science Foundation of China(No.11474172)
文摘A double-zone aspheric diffractive intraocular lens （IOL） was designed and manufactured aiming to regain a continuous range of clear vision for pseudophakic presbyopia. After obtaining the IOL structure parameters through optimization based on an aphakic model eye, its imaging performances were analyzed in the model eye. The modulation transfer function at 50 cycles/mm remained above 0.29 within ±5° field of view for object distance ranging from 6 to 0.66 m. In addition, the imaging qualities are robust for pupil changes, polychromatic light, and different corneal asphericities. The manufactured IOL exhibits the abilitv to extend depth of focus.
文摘We show the power of spirally polarized doughnut beams as a tool for tuning the field distribution in the focus of a high numerical aperture （NA） lens. Different and relevant states of polarization as well as field distributions can be created by the simple turning of a λ/2 retardation wave plate placed in the excitation path of a micro- scope. The realization of such a versatile excitation source can provide an essential tool for nanotechnology investigations and biomedical experiments.
