Design Of Lens System Research Articles

Design and analysis of the liquid lens system for bionic human eye imaging

In this paper, the liquid lens system for bionic human eye imaging is designed based on the principles of dielectrophoretic drive and hydraulic drive. The core part of this lens system is the biconvex liquid lens of the bionic human eye crystalline lens. Based on this part, a PDMS membrane liquid lens module and a liquid chamber are added, which are combined with the biconvex liquid lens to form a structure that can be used to represent the cornea, the anterior chamber, the vitreous body and other parts of the human eye. It is a combined structural design to realize the whole human eye liquid lens system. The design of the system model and the analysis of ray tracing are mainly accomplished with COMSOL software, and the experimental research of the system is carried out. The whole liquid lens device for the bionic human eye is fabricated; its zoom characteristics and imaging resolution are measured at fixed volumes of liquid injection with different voltages and at fixed voltages with different volumes of liquid injection, respectively. The results show that the zoom range of the liquid lens system for bionic human eye imaging is 24.81mm-13.07 mm, which can reflect the zoom characteristics of general human eyes, and its imaging resolution can reach a maximum of 90.51lp/mm.

Dual-channel aperture-splitting snapshot spectral imaging detection system

The contemporary spectral imaging detection systems commonly employed, such as pushbroom and stare systems, often necessitate motion-based imaging mechanisms such as scanning motors. This reliance on motion renders the imaging process vulnerable to platform vibrations, resulting in intricate post-image correction procedures and precluding dynamic target detection. Consequently, the advent of snapshot spectral imaging detection systems has ensued. Currently, there are significant challenges in the miniaturization design and rapid data acquisition aspects of snapshot spectral imaging systems. In this study, linear variable filters were employed as spectral components, and, through optical system simulation and design, the design of the nonspherical monolithic lens system and telescope system in the dual-channel aperture-splitting snapshot spectral imaging detection system were separately completed. The spectral range covered 400–1000 nm, with a spectral resolution of 27.3 nm, and each channel had a spatial sampling of 409×409 pixels. Additionally, based on the optical system design results, the system structure design and assembly were completed. Performance testing and preliminary spectral image fusion research were conducted on the assembled prototype. The instrument demonstrated excellent spectral imaging performance, thereby enhancing the efficiency of spectral imaging detection in snapshot spectral imaging.

Single-fiber probes for combined sensing and imaging in biological tissue: recent developments and prospects.

Single-fiber-based sensing and imaging probes enable the co-located and simultaneous observation and measurement (i.e., 'sense' and 'see') of intricate biological processes within deep anatomical structures. This innovation opens new opportunities for investigating complex physiological phenomena and potentially allows more accurate diagnosis and monitoring of disease. This prospective review starts with presenting recent studies of single-fiber-based probes for concurrent and co-located fluorescence-based sensing and imaging. Notwithstanding the successful initial demonstration of integrated sensing and imaging within single-fiber-based miniaturized devices, the realization of these devices with enhanced sensing sensitivity and imaging resolution poses notable challenges. These challenges, in turn, present opportunities for future research, including the design and fabrication of complex lens systems and fiber architectures, the integration of novel materials and other sensing and imaging techniques.

A new approach for fast field calculation in electrostatic electron lens design and optimization

In electron optics, calculation of the electric field plays a major role in all computations and simulations. Accurate field calculation methods such as the finite element method (FEM), boundary element method and finite difference method, have been used for years. However, such methods are computationally very expensive and make the computer simulation challenging or even infeasible when trying to apply automated design of electrostatic lens systems with many free parameters. Hence, for years, electron optics scientists have been searching for a fast and accurate method of field calculation to tackle the aforementioned problem in the design and optimization of electrostatic electron lens systems. This paper presents a novel method for fast electric field calculation in electrostatic electron lens systems with reasonably high accuracy to enable the electron-optical designers to design and optimize an electrostatic lens system with many free parameters in a reasonably short time. The essence of the method is to express the off-axis potential in an axially symmetrical coordinate system in terms of derivatives of the axial potential up to the fourth order, and equate this to the potential of the electrode at that axial position. Doing this for a limited number of axial positions, we get a set of equations that can be solved to obtain the axial potential, necessary for calculating the lens properties. We name this method the fourth-order electrode method because we take the axial derivatives up to the fourth order. To solve the equations, a quintic spline approximation of the axial potential is calculated by solving three sets of linear equations simultaneously. The sets of equations are extracted from the Laplace equation and the fundamental equations that describe a quintic spline. The accuracy and speed of this method is compared with other field calculation methods, such as the FEM and second order electrode method (SOEM). The new field calculation method is implemented in design/optimization of electrostatic lens systems by using a genetic algorithm based optimization program for electrostatic lens systems developed by the authors. The effectiveness of this new field calculation method in optimizing optical parameters of electrostatic lens systems is compared with FEM and SOEM and the results are presented. It should be noted that the formulation is derived for general axis symmetrical electrostatic electron lens systems, however the examples shown in this paper are with cylindrical electrodes due to the simplicity of the implementation in the software.

Design of a panoramic annular lens system with an ultra-wide angle via an annular Gaussian radial basis function freeform surface.

The panoramic annular lens (PAL) system can capture plentiful scene information in real time. The locally described freeform surface can provide more degrees of freedom for the optical system design than the globally described one. In this paper, we propose a locally described annular Gaussian radial basis function freeform surface that enables a high-performance yet compact PAL system. The designed PAL system achieves an ultra-wide field of view (FOV) of (30∘∼125∘)×360∘. The F-theta distortion of the system is less than 3%, and the modulation transfer function across the whole FOV is greater than 0.5 at 100lp/mm. The proposed system can be implemented for various applications such as video conferencing or robotic navigation.

Design and Fabrication of a Continuous Zoom Liquid Micro-Cylindrical Lens System

Design and Fabrication of a Continuous Zoom Liquid Micro-Cylindrical Lens System

Paraxial design of four-component zoom lens system with fixed distance between focal points by matrix optics

In this paper, we propose a systematic approach to design a four-component zoom system with fixed spacing between focal points based on matrix optics to achieve a relatively high zoom ratio. In the method, the zoom trajectory under each chosen paraxial design is determined through matrix method, which is challenging but meaningful to achieve a globally optimized design for the complex zoom system. The elements of the system matrix imply the working state of the optical system, and axial displacement equation for the desired zoom system are derived by restricting specific matrix elements. Properly selected trajectory of the particular component described by means of a parametric function can make the model become solvable explicitly. Then the paraxial design problem is transformed into the optimization of these parameters with regard to the merit functions encompassing the primary aberration terms, compactness, smoothness of the trajectories. We adopt Particle Swarm Optimization (PSO) algorithm to globally optimize the parameters to retrieve the optimum zoom trajectory in specific design criteria. The proposed method is demonstrated through two specific examples under different configurations, both of which have acquired a final zoom ratio of 8X. The simulation results demonstrate that our proposed method can be a practical and powerful tool for paraxial design of complex multi-group zoom optical systems.

Compact and lightweight panoramic annular lens for computer vision tasks.

We propose a focal power distribution theory for the design of a compact panoramic annular lens (PAL) system based on Petzval sum correction. The system has a large field of view (FoV) of 360° ×(25°-100°). Its total length is 29.2 mm and weight is only 20 g. The proposed compact PAL system achieves large FoV and loose tolerances while maintaining small volume and low cost. It solves the shortcomings of traditional PAL systems that cannot be mounted on miniaturized portable devices due to their large volume and weight. We equip the compact PAL system with a novel and customized image enhancement model: PAL-Restormer to achieve better imaging quality. The produced images are further evaluated in various panoramic environment perception tasks. Extensive experiments show the promising potential of our proposed compact PAL system for the applications in wearable devices and mobile robots.

Design of IR zoom lens system for long-range detection in uncooled LWIR camera

A new compact optical zoom lens system with variable focal length 100–200 mm for uncooled LWIR (8–12 μm) camera is designed. It is used for long-range detection. The optimized IR zoom lens consists of four group elements. The F/# of the zoom system is F/1.4 at all zoom positions. Its performance reaches the diffraction limit at each focal length position. Moreover, optical design and image quality are calculated by ZEMAX optical software. The imaging quality performance is steady during zoom process. In addition to the above benefits, the optimized IR zoom lens is light and compact (200 mm) with 4 lenses and only one of them has diffractive surface to lower production cost. Upon applying anti-reflection coating, the total transmittance of the optical system is enhanced from 2 to 99% at λ = 10 µm.

Van der Waals Semiconductor Empowered Vertical Color Sensor.

Biomimetic artificial vision is receiving significant attention nowadays, particularly for the development of neuromorphic electronic devices, artificial intelligence, and microrobotics. Nevertheless, color recognition, the most critical vision function, is missed in the current research due to the difficulty of downscaling of the prevailing color sensing devices. Conventional color sensors typically adopt a lateral color sensing channel layout and consume a large amount of physical space, whereas compact designs suffer from an unsatisfactory color detection accuracy. In this work, we report a van der Waals semiconductor-empowered vertical color sensing structure with the emphasis on compact device profile and precise color recognition capability. More attractive, we endow color sensor hardware with the function of chromatic aberration correction, which can simplify the design of an optical lens system and, in turn, further downscales the artificial vision systems. Also, the dimension of a multiple pixel prototype device in our study confirms the scalability and practical potentials of our developed device architecture toward the above applications.

Automated lens design for optical systems consisting of stock lenses.

The design of lens systems requires advanced knowledge and the mastery of highly specialized software tools. Furthermore, for the realization of the designed lens systems often custom-made lenses are needed, which are expensive and have lead times of several weeks compared to stock lenses with several days. To shorten realization time, a new approach for the automated design of lens systems consisting of stock lenses is developed. In this work, a multi-step process is described which identifies the most robust stock lens combination fulfilling prior defined requirements. The approach is realized with a computer program that can be used by a non-expert to find the most suited selection of stock lenses for a three-lens system for a set of requirements.

A three-dimensional velocity-map imaging setup designed for crossed ion-molecule scattering studies

In this study, we report the design and simulation of an electrostatic ion lens system consisting of 22 round metal plates. The opening of the extractor plate is covered with metal mesh, which is for shielding the interaction region of the lens system from the high DC voltages applied to all other plates than the repeller and extractor plates. The Simion simulation shows that both velocity-mapping and time focusing can be achieved simultaneously when appropriate voltages are applied to each of the plates. This makes the ion lens system be able to focus large ionic volumes in all three dimensions, which is an essential requirement for crossed ion-molecule scattering studies. A three-dimensional ion velocity measurement system with multi-hit and potential multi-mass capability is built, which consists of a microchannel plate (MCP), a P47 phosphor screen, a CMOS camera, a fast photomultiplier tube (PMT), and a high-speed digitizer. The two velocity components perpendicular to the flight axis are measured by the CMOS camera, and the time-of-flight, from which the velocity component along the flight axis can be deduced, is measured by the PMT. A Labview program is written to combine the two measurements for building the full three-dimensional ion velocity in real time on a frame-by-frame basis. The multi-hit capability comes from the fact that multiple ions from the camera and PMT in the same frame can be correlated with each other based on their various intensities. We demonstrate this by using the photodissociation of CH3I at 304 nm.

A Freeform Lens System Design and Simulation in the Polar Coordinate

In the field of illumination engineering, freeform technology is playing a more and more important role. Several methods have been reported in recent papers. The paper introduce a design method to generate an ellipse spot in the polar coordinate using the polar grids based on flux transportation mapping. In this method, the source is a point and the point is divided along the azimuth angle and zenith angle in the polar coordinate system. Then we divided the flux target in the polar coordinate, the grids of the target are achieved by the mapping between the source and the target. Based on the mapping and energy conservation, we can derive a set of the first-order PDE according to Snell’s law. We can acquire a points cloud after solving the PDE numerically, then we will construct a smooth freeform using Rhino. Finally, we will test the freeform using Light Tools. With this method, we can design a lens with the light utilization efficiency over 0.8. Keywords: LED; Freeform; Mapping; Polar coordinate.

多组元全动型大孔径及超大视场变焦系统设计

多组元全动型大孔径及超大视场变焦系统设计

Fish-eye lens system design based on sixth-order wave aberration theory

Fish-eye lens system design based on sixth-order wave aberration theory

Design, development, and performance comparison of wide field lensless and lens-based optical systems for point-of-care biological applications

Lensless biological imaging systems are an emerging alternative to conventional microscopic systems because they enable a wide field of view imaging. While most microscopic systems sacrifice the field of view for magnification, lensless systems have taken advantage of small imaging pixel size, projection, digital magnification, and post-processing to compensate for diffracted images. A new lens-based system is designed to have the exact same wide field of view as that of a basic lensless setup. A new compound lens system design is utilized to achieve an explicit aim to have the same fields of view as the lensless setup. Then the characteristics of these two optical imaging setups (lensless and lens-based setups) are compared at this level of complexity to see what the minimal systems principles are needed to achieve the biological imaging goals for simplified and less expensive future designs. For both imaging systems, images of biological entities are recorded with the help of the same CMOS imaging device and computer software. The main contribution of this work is an exhaustive comparison between the performance characteristics of both systems using optical standards and biological images.

Designing an anamorphic illumination system with an RTIR prism for a tilt-and-roll-pixel-type projector.

A relay lens system design for a mini-projector with telecentric illumination is described. The reverse total internal reflection (RTIR) prism for angular magnification and lateral magnification is discussed in detail, and magnifications under different digital micromirror devices (DMD) are compared. The tilt-and-roll pixel (TRP) DMD chip (tilt angle is ${\pm 17}^\circ $±17∘) is the latest spatial light modulator, and the f-number of the illumination system is 1.71. Using the TRP DMD, the lateral magnification and the angular magnification for the RTIR prism can be increased by 3.77% and 8.73% over that obtainable using the conventional DMD chip (tilt angle is ${\pm 12}^\circ $±12∘). In order to solve for the angular magnification of an RTIR prism, the baffle is set at the aperture stop of the relay lens system. There is a trade-off between the efficiency and the contrast ratio with the baffle. When B (the position of the baffle) is at 0.11, the contrast ratio of the illumination system is 7590:1 and the efficiency is 57%. The spot size at the edge and corner of the DMD active area is controlled to be less than 250 µm, and the optical distortion is less than 1%.

变焦鱼眼镜头系统设计

变焦鱼眼镜头系统设计

Globally optimal first-order design of zoom systems with fixed foci as well as high zoom ratio.

In this paper, we propose a systematic approach to automatically retrieve the first-order designs of three-component zoom systems with fixed spacing between focal points based on Particle Swarm Optimization (PSO) algorithm. In this method, equations are derived for the first-order design of a three-component zoom lens system in the framework of geometrical optics to decide its basic optical parameters. To realize the design, we construct the mathematical model of the special zoom system with two fixed foci based on Gaussian reduction. In the optimization phase, we introduce a new merit function as a performance metric to optimize the first-order design, considering maximum zoom ratio, total optical length and aberration term. The optimization is performed by iteratively improving a candidate solution under the specific merit function in the multi-dimensional parametric space. The proposed method is demonstrated through several examples, which cover almost all the common application scenarios. The results show that this method is a practical and powerful tool for automatically retrieving the optimal first-order design for complex optical systems.

Design, simulation and characterization of fly-eye lens system for optical wireless power transmission

Optical wireless power transmission (OWPT) has numerous advantages. To obtain high efficiency of the OWPT, the fly-eye lens system is attractive for improving system efficiency due to the suppression of light leakage and non-uniform light irradiation. Numerical design and analysis were performed to obtain the optimal configuration of the lens system. From the experiment, a rectangular and uniform irradiated pattern was confirmed, and the power transmission characteristics were characterized. Furthermore, we proposed a configuration that can increase the allowable incident angle by attaching a fly-eye lens to the solar cell side. This configuration is effective as a construction method of the OWPT system that can ease the installation and improve the reliability of beam position fluctuation.