共查询到20条相似文献,搜索用时 0 毫秒
1.
We present a procedure for designing to control the three-dimensional light-intensity distribution near focus. Our method is based on the use of a series of figures of merit that are properly defined to describe the effect of general complex pupil functions. As a practical implementation, we have applied our method to obtain super resolving continuous smoothly varying phase-only filters. The advantages of these kinds of filters are that they do not produce energy absorption and they are easy to build with a phase-controlling device such as a deformable mirror. Results of comparisons between the performance of our method and that of other phase-filter designs are provided. 相似文献
2.
In this paper, a new method for designing three-zone optical pupil filter is presented. The phase-only optical pupil filter and the amplitude-only optical pupil filters were designed. The first kind of pupil for optical data storage can increase the transverse resolution. The second kind of pupil filter can increase the axial and transverse resolution at the same time, which is applicable in three-dimension imaging in confocal microscopy. 相似文献
3.
4.
5.
Two models have been established using the basic definitions of super-resolution characteristic parameters for normalized spot size GA and Strehl ratio SA, of a three-zone axial super-resolution pupil filter with fabrication errors, to quantitatively analyze the effect of these fabrication errors on the axial super-resolution property. These new models established to describe the analytic relationship of GAe and SAe of a pupil filter with its fabrication errors and its transmission function A(ρ), phase function φ(ρ) and structural parameters, directly relate the super-resolution parameters of a three-zone axial super-resolution pupil filter to its fabrication errors to make the quantitative analyses of the effect of fabrication errors easier, thereby providing a theoretical basis for the analysis, design and fabrication of a three-zone axial super-resolution pupil filter. The models established for GAe and SAe have been used to analyze the effect of the fabrication errors of a pupil filter on its super-resolution property, with a three-zone phase-only pupil filters as example. 相似文献
6.
Two models have been established using the basic definitions of super-resolution characteristic parameters for normalized spot size GT and Strehl ratio ST of a three-zone lateral super-resolution pupil filter with fabrication errors to quantitatively analyze the effect of these fabrication errors on the lateral super-resolution property. These new models established to describe the analytic relationship of GTe and STe of a pupil filter with its fabrication errors and its transmission function A(ρ), phase function φ(ρ) and structural parameters directly relate the super-resolution parameters of a three-zone lateral super-resolution pupil filter to its fabrication errors to make the quantitative analyses of the effect of fabrication errors easier, thereby providing a theoretical basis for the analysis, design and fabrication of a three-zone lateral super-resolution pupil filter. The models established for GTe and STe have been used to analyze the effect of the fabrication errors of a pupil filter on its super-resolution property with a three-zone phase-only pupil filter as an example. 相似文献
7.
The performance of pupil filters consisting of three zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters. 相似文献
8.
The performance of pupil filters consisting of two zones each of constant complex amplitude transmittance is investigated. For filters where the transmittance is real, different classes of potentially useful filter are identified and optimized. These include leaky filters with an inner zone of low amplitude transmittance, pure phase filters with phase change of π, and equal area filters. The first of these minimizes the relative power in the outer rings for a given axial resolution, the second maximizes the Strehl ratio for a given transverse resolution, and the third minimizes the relative power in the outer rings for a given transverse resolution. Complex filters can give an axially shifted maximum in intensity: the performance parameters calculated relative to the true focus are investigated for some different classes of filter, but filters with phase change not equal to π are found to give inferior performance to the real value filters. 相似文献
10.
This paper reports the study of superresolution and extension of depth of focus (DOF) of three-zone binary phase filters (BPFs) under high numerical aperture (NA) focusing. Two three-zone BPFs (BPF1 and BPF2) are specially designed to achieve transverse superresolution and extension of DOF simultaneously for the optical disc system with an objective lens of NA = 0.65. Numerical simulations based on the vectorial diffraction theory indicate that the transverse focal spot size of this system can be as small as that of NA = 0.85 and its DOF is as large as that of NA = 0.6 with acceptable Strehl ratios (> 0.4 for BPF1 and > 0.35 for BPF2) and low side-lobe intensity ratios (< 10%) by using these BPFs. It suggests that the storage capacity of this optical storage system may be improved to the same as that of a system with an objective lens of NA = 0.85. Moreover, the strict requirement of the focusing servo system caused by decreasing wavelength or employing higher NA objective lens can be mitigated. Therefore, these BPFs presented in this paper should be highly interesting for applications of high density optical data storage. 相似文献
11.
We propose a simple method of designing pupil filters for transverse super-resolution. For this end we represent the amplitude Point Spread Function (PSF) as a series expansion, constructed from the Fourier transform of a basis of Bessel functions. With this representation we optimize the intensity PSF according to certain desired characteristics, such as a smaller disk diameter than the corresponding, clear aperture, Airy disk. It is proved that by using few basis functions, it is possible to design pupils with similar or better PSF characteristics than previously reported. 相似文献
12.
Superresolution is very important in imaging and optical storage systems, and has attracted much attention. In this article, concentric three-zone phase plate with 0, π, 0 phase variation has been investigated numerically to show that this kind of phase plate can be used to obtain three-dimensional superresolution. In addition, the number of intensity maximum, focal depth, focal shift, full-width half-maximum, and relative intensity of side lobe are listed for different radii of the phase zones, which paves the way for design of the phase plate. Therefore, one can choose values of radii for desired intensity distribution in focal region, such as for the purpose of radial superresolution with high focal depth in optical storage. 相似文献
13.
A new set of tunable phase-only filters for realizing the transverse superresolution is introduced.The filters,whose significant features are their ability to tune and simplicity,consist of one half-wave plate between two quarter-wave plates,and the half-wave plate is made of two zones that can rotate with respect to each other.Through analyzing the transverse point spread function of such system,it can be concluded that by rotating any zone of the half-wave plate,the transverse resolution can be realized and can be tunable. 相似文献
14.
15.
为克服传统光瞳滤波器的缺点,实现系统光学超分辨性能的可调谐性,设计了一种新型可调谐的位相型光瞳滤波器.该光瞳滤波器包括两个λ/4波片和置于其间的λ/2波片,其中λ/2波片分为两个可作相对旋转的区域.研究结果表明,通过旋转λ/2波片的任意一区域不仅可以实现系统横向光学超分辨能力的可调性,而且可以在横向分辨能力提高的同时实现光学系统轴向焦深的扩展以及轴向焦移.
关键词:
光学超分辨
位相型光瞳滤波器
可调谐 相似文献
16.
This paper investigates the influences of phase shift on superresolution
performances of annular filters.
Firstly, it investigates the influence of phase shift on axial
superresolution.
It proves theoretically that axial superresolution can not
be obtained by two-zone phase filter with phase shift π, and it
gets the
phase shift with which axial superresolution can be brought by two-zone
phase filter. Secondly, it studies the influence of phase shift on transverse
superresolution. It finds that the three-zone phase filter with arbitrary phase
shift has an almost equal optimal transverse gain to that of commonly used
three-zone phase filter, but can produce a much higher axial
superresolution gain. Thirdly, it investigates the influence of phase shift on
three-dimensional superresolution. Three-dimensional
superresolution capability and design margin of three-zone complex filter
with arbitrary phase shift are obtained, which presents the theoretical
basis for three-dimensional superresolution design. Finally, it
investigates the
influence of phase shift on focal shift. To obtain desired focal shifts,
it
designs a series of three-zone phase filters with different phase shifts. A
spatial light modulator (SLM) is used to implement the designed filters. By
regulating the voltage imposed on the SLM, an accurate focal shift control
is obtained. 相似文献
17.
18.
提出一种基于渐进空间映射算法(ASM)与遗传算法(GA)相结合的I/O端口不等长相移效应的滤波器快速调试方法。渐进空间映射算法能够准确预测精细模型的调试方向与幅度,遗传算法能够准确快速得到I/O端口的相移效应,并且通过柯西法提取粗糙模型。基于有限元的全波电磁仿真软件HFSS, 建立精细模型,粗糙模型参数即等效电路参数, 则由去除I/O端口处相移效应后的S参数获得。利用该方法对六阶交叉耦合滤波器进行调试,经过几步迭代即可使滤波器满足所要求的响应指标,验证了该调试方法的正确性和有效性。 相似文献
19.
20.
用矢量衍射方法分析了线偏振光入射到带有三环位相型光瞳滤波器的高数值孔径物镜时,焦点的轴向和横向光强分布.数值模拟结果表明,高数值孔径物镜聚焦时需同时考虑光强的轴向和横向分布.通过加入三环位相光瞳滤波器,在实现横向超分辨的同时实现了光学系统轴向焦深扩展和轴向光强分布平坦化,并且位相调制深度变化时,会出现轴向焦移现象.对三环位相光瞳滤波器结构进行了优化,得出了优化结果.
关键词:
光学超分辨
扩展焦深
位相型光瞳滤波器
矢量衍射方法 相似文献