Single-lens equivalent systems for Grin lenses

In this paper, one simple single-lens optical systems equivalent to Grin lens of various lengths, which are immersed in either homogeneous or inhomogeneous medium, are proposed. Basing on this equivalent system, the imaging properties of Grin lens rod in paraxial approximation have been thoroughly studied. The proposed plain optical system will lead to a straightforward optical analysis of complex optoelectronics systems employing Grin lens rod.     

自聚焦透镜的三维相干成像特性分析

运用傅里叶光学方法，分析并推导了自聚焦透镜的三维相干成像公式。研究表明，虽然自聚焦透镜中介质折射率是径向渐变折射率分布，不同于薄透镜中的均匀分布，但是由于它的三维相干成像性质却类似于薄透镜，从而使自聚焦透镜可以在成像和光学信息处理系统中有效地代替薄透镜，实现光学系统的微型化。     

球面端面的锥形梯度折射率透镜的近轴成像特性

本文根据光线在球面上的折射公式及光线微分方程,研究了光线经两端面为球面的锥形梯度折射率透镜的传播和变换,基于光线传递ABCD矩阵,提出了球面端面的锥形梯度折射率透镜的一种等效光学系统.文中给出了该透镜的主平面、焦平面和焦距计算公式,以及近轴成像高斯公式.当锥度为零时即得到球面端面的柱形或径向梯度折射率透镜的相应结果.     

替代旋转非球面的GRIN透镜的理论分析

本文通过对轴向球面GRIN透镜的分析,导出了光线在透镜内部传输的一般方程利用等光程方法导出了轴向GRIN透镜与旋转非球面匀质透镜之间的等效条件。     

非圆柱形发散梯度折射率棒透镜光线传播轨迹的解析解族

本文研究光线在具有非圆柱形等折射率面的发散型梯度折射率棒透镜中的传播规律,提出在轴向弱非匀条件(即dg~(-1)(z)/dz<<1下近轴子午光线轨迹的一种解析表达式.从该解析式的解析解,棒透镜梯度参数g(z)所满足的条件出发,导出棒透镜的折射率分布族.文中给出了两个线性无关的光线传播轨迹的解析解族,并以一种发散型棒透镜为例讨论了近轴成像特性.     

GRIN透镜干涉仪光学系统模型和分析

较完整地提出GRIN透镜干涉仪的数学模型,分析了光学系统处于六种不同模态下的特点,讨论了有关结构因素,特别是GRIN透镜长度对干涉仪工作性能的影响,有关分析和相关结论可作为GRIN透镜干涉仪系统设计和测量计算的依据。     

超小自聚焦光纤探头的研究进展

梯度折射率（Gradient-index,GRIN）光纤探头是一种全光纤型超小光学镜头,在心血管等狭小空间组织内窥影像检测中具有广阔的应用前景。但其发展一直缺少系统的理论体系。本文讨论探头设计、制作和性能测试等方面的关键问题。基于GRIN光纤探头聚焦性能的特征参数,对解析设计方法与数值仿真设计方法进行比较分析。针对超小GRIN光纤探头的制作难题,研究一种光纤熔接和切割的高精度一体化集成装置,描述GRIN光纤探头的制作方法。此外,分析了超小GRIN光纤探头聚焦性能检测的方法及装置。本文为超小GRIN光纤探头的设计、制作及性能测试提供了一个方法体系。     

Numerical simulation of a gradient-index fibre probe and its properties of light propagation

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.     

方形自聚焦透镜5×5阵列的成像特性

采用离子交换工艺和精密加工技术制作了方形自聚焦透镜5×5阵列,并对其成像特性进行研究。结果表明：方形自聚焦透镜阵列相对于圆形孔径阵列而言,能有效增大填充系数,提高受光面积,其多重像和综合像的像质均匀,成像质量好。分析了导致多重像偏离和综合像变形的原因,并给出解决这一问题的关键技术。     

自聚焦透镜离轴耦合损耗理论研究

利用光线光学的原理分析了自聚焦透镜的光学性能,提出了求解自聚焦透镜离轴耦合损耗的数学模型,利用这一模型计算出了单模光纤与自聚焦透镜离轴耦合时的耦合损耗与模向距离的关系曲线,为自聚焦透镜离轴耦合的设计提供理论依据.     

梯度折射率球透镜的制备及其光线轨迹测试

自麦克斯韦鱼眼透镜理论模型提出后,长期以来学术界一直以为它只是一种绝对光学仪器,在实践中并没有应用的可能。但通过对麦克斯韦鱼眼微球透镜的理论研究表明,在一定条件下,它具有良好的成像性能和耦合效率。根据菲克定律推导出梯度折射率球透镜的折射率分布函数。并且熔制了含Li+硅酸盐玻璃和采用槽沉法以及Na+/Li+离子交换法制备直径为0.3—3.0mm的梯度折射率球透镜。通过干涉法测得了梯度折射率球透镜的折射率分布曲线,并研究了光线通过梯度折射率球透镜的轨迹。研究结果表明:在590℃,离子扩散系数为3.07×10-6mm2/s;所制备的梯度折射率球透镜的折射率分布是抛物线分布,并且和理论分析相吻合;梯度折射率球透镜的光线轨迹满足椭圆方程。     

Automatic design of a one-to-many optical-interconnects lens system using aspherics

Use of an aspherical surface in the design of a lens system for one-to-many optical-interconnects (OTM-OI), composed of a doublet lens and a gradient-index (GRIN) lens array has been investigated. Applying the procedure of ALSIE (Automatic Lens design by Solving InEqualities), the off-axis lens systems, which feature the optical performance of the OTM-OI lens system, are optimized at 0.1 numerical aperture with a total field of view of 2°. Three aspherical designs with the aspherical surface for different surfaces are presented. The aspherical designs show preferable modulation transfer function (MTF) for high frequency as compared with the spherical design.     

一种具有Luneburg透镜特性的轴向GRIN介质透镜

本文给出一种轴向GRIN(梯度折射率)介质透镜。这种透镜具有 Luneburg(卢内堡)透镜的特性。它可以使无限远光线锐成象;亦可用于点—点锐成象系统,光准直或光准直—聚焦系统;在微波频谱区域及有声成象、天线设计方面有一定应用价值。     

Fabrication of gradient refractive index ball lenses

The theoretical model of the Maxwell fish eye sphere lens has long been regarded as an absolute optical instrument without practical application since it was proposed. But the study on the theory of Maxwell fish eye micro-spherical lens shows that at certain condition it has fine image formation ability and coupling efficiency. Based on the Fick's diffusion equations, the distribution function of refractive index of gradient refractive index (GRIN) ball lenses is derived. Lithium-containing silicate glass is fabricated and GRIN ball lenses whose diameters are from 0.3 to 3.0 mm are made by ion exchange and the sagging method in sodium nitrate. Radial refractive index profiles of these GRIN ball lens are measured by interferometer. Results show that the distribution of the index of refraction is a parabolic curve and in concordance with the computational consequence and its Δn is 0.0002.     

失调分数傅里叶变换及其光学作用

利用失调光学系统的衍射积分公式,分析了失调的Lohmann分数傅里叶变换光学系统和准非对称非均匀介质的衍射特性,得到了两者具有相同的失调衍射积分表达式,表明两者具有等效性,从中提出了失调分数傅里叶变换新概念. 关键词： 分数傅里叶变换 失调光学系统 衍射积分 梯度折射率介质     

A proposal for wavelength-tuning and stabilization of GaAs lasers with a graded-index fibre segment in a dispersive cavity

We suggest a scheme for controlling the wavelength of a GaAs injection laser by coupling it to one of the flat ends of a short segment (～6 mm long, 2.5 mm diameter) of graded-index (GRIN) rod, the other end of which has a diffraction grating deposited on it. Tuning is accomplished by sliding the diode off the optical axis of the rod. The lasing wavelength is not temperature dependent as it is determined only by geometrical factors and thef-number of the GRIN lens, and a spectral resolution of 0.25 to 0.5 nm can be achieved. The significance of this on the performance of optical communication systems is discussed. The possibility ofelectrically controlling the wavelength with a nematic liquid crystal diffraction grating is also pointed out.     

Effect of crystalline lens surfaces and refractive index on image quality by model simulation analysis

The surfaces and refractive index of crystalline lens play an important role in the optical performance of human eye.On the basis of two eye models,which are widely applied at present,the effect of lens surfaces and its refractive index distribution on optical imaging is analyzed with the optical design software ZEMAX (Zemax Development Co.,San Diego,USA).The result shows that good image quality can be provided by the aspheric lens surfaces or (and) the gradient-index (GRIN) distribution.It has great potential in the design of intraocular lens (IOL).The eye models with an intraocular implantation are presented.     

Amplified optical window for three-dimensional images

A proposed amplified optical window can form an observable three-dimensional image of an object in darkness. The window comprises two gradient-index (GRIN) lens arrays with an image intensifier between them. The length of the individual GRIN lenses that constitute the arrays is three fourths of the cycle of the meandering optical path on the input side and one fourth of the cycle on the output side. A primitive experimental result proved that the method produces three-dimensional images to be observed. This device would be used as a viewer for observing three-dimensional objects in a dark space without a camera and display equipment.