Proceedings Volume 12217

Current Developments in Lens Design and Optical Engineering XXIII

cover
Proceedings Volume 12217

Current Developments in Lens Design and Optical Engineering XXIII

Purchase the printed version of this volume at proceedings.com or access the digital version at SPIE Digital Library.

Volume Details

Date Published: 3 October 2022
Contents: 8 Sessions, 27 Papers, 18 Presentations
Conference: SPIE Optical Engineering + Applications 2022
Volume Number: 12217

Table of Contents

icon_mobile_dropdown

Table of Contents

All links to SPIE Proceedings will open in the SPIE Digital Library. external link icon
View Session icon_mobile_dropdown
  • Front Matter: Volume 12217
  • Theory and Applications I
  • Developments in Optical Components, Techniques, and Materials
  • Simulation of Optical Systems
  • Modeling and Illumination
  • Integration of Optical Designs into Complete Instruments
  • Theory and Applications II
  • Poster Session
Front Matter: Volume 12217
icon_mobile_dropdown
Front Matter: Volume 12217
This PDF file contains the front matter associated with SPIE Proceedings Volume 12217, including the Title Page, Copyright information, Table of Contents, and Conference Committee Page.
Theory and Applications I
icon_mobile_dropdown
Simultaneous multiple surfaces method applied to infrared lenses
T. Mayeur, J. B. Volatier, G. Druart, et al.
In optical design, the designer's experience is critical. Indeed, an experienced optical designer will often choose a better starting point for optimization than an inexperienced one. Most of the time, lens design software use a local optimization algorithm, which is why the starting point is so important to get an excellent optical system. We present here an alternative to the classical optical design method and a solution to reduce the impact of the designer's experience. Our alternative couples the Simultaneous Multiple Surfaces (SMS) method, introduced by Benítez and Miñano with optimization in Zemax OpticStudio. The SMS method is a direct construction method of optical systems without optical aberrations for as many field points as the system contains surfaces. This method can deal with both aspheric and freeform optical systems depending on the dimension of the method implemented. Our implementation of the SMS method can design optical systems with three surfaces. We use the SMS method to define a freeform system with an F-number of 0.85. Then, we use this fast freeform system as a starting point to perform further optimization in Zemax OpticStudio. Finally, we achieve to design two diffraction-limited freeform systems, one over a square field of view of ±30° and another over a rectangular field of view of ±33° × ±26°.
Through focus point spread function and modulus transfer function for multifocal lenses
A system for measuring the through-focus point spread function (PSF) for intra-ocular lenses (IOLs) and converting to modulation transfer function (MTF) is developed. The system consists of a light source, eye model, IOL, magnifier, and CCD camera. By capturing the resulting image through a range of focus positions, the PSF is found and converted to MTF. The MTF displays differences in the depth of focus for monofocal, multifocal, and extended depth of focus (EDOF) IOLs. As multifocal and EDOF IOLs evolve, using the MTF to predict the image quality is vital to implanting the most appropriate lens in the patient’s eyes.
Multifocal lens HDR image simulation showing dysphotopsia
A system is developed for simulating the image quality and dysphotopsia of multifocal lenses. To achieve this, the simulation modifies a High Dynamic Range (HDR) photograph by blurring it with the lens’ point spread function in MATLAB. Dysphotopsias are instances of unwanted or missing light within the eye. Common forms of dysphotopsia include glare, starburst (radial lines emanating from bright sources), and halo (rings of light surrounding bright sources) with the latter two typically occurring at night or in other high contrast settings. Dysphotopsia is considered the most common complaint of patients after successful cataract surgery and have thus earned significant attention in the context of intraocular lenses (IOLs). There have been fewer studies of multifocal contact lens dysphotopsia, but this is despite the documented impact dysphotopsia has on the image quality of multifocal lenses. This simulation is the first handling of dysphotopsia that combines HDR images and specifics of the lens design to predict how the dysphotopsia will appear to patients. Being able to show patients accurate simulations of dysphotopsia has the benefit of setting proper patient expectations before they begin using multifocal lenses. Furthermore, these simulated images can also potentially help diagnose patient problems by giving patients an accurate baseline to compare to.
Passive athermalization of MWIR optical designs utilizing different infrared optical materials
In this paper, different optical designs, which are composed of different MWIR optical materials, are utilized for passive athermalization and their performance in athermalization are analyzed. The optical designs are carried out by preserving the athermal property as well as keeping the image quality at higher levels within the working temperature between –40 ºC and +60 ºC. The passive athermalization process begins with the calculation of athermalization conditions of candidate material properties. By considering these conditions, athermal material pairs are chosen. To reduce optical aberrations, aspherical surfaces are utilized during the optimization process. At the end of the design phase, the performance of different configurations of athermal optical material pairs, which are enclosed by aluminum alloy housing material, are presented.
Developments in Optical Components, Techniques, and Materials
icon_mobile_dropdown
Latest advancements at NILT on flat metalens based camera modules in near infrared
Fredrik Mattinson, Ulrich Quaade, Villads Egede Johansen, et al.
NIL Technology (NILT) is an optical solutions company designing, developing, and manufacturing flat optical elements and components with nanoscale features such as diffractive optical elements (DOEs) and meta optical elements (MOEs). NILT’s MOE lenses have recently demonstrated a groundbreaking 94% absolute efficiency at 940 nm. This major milestone, in combination with other efforts such as the subsequent module integration and enabling of mass production of MOE elements, are among the key development areas for successful adoption of MOE lenses in various markets, ranging from consumer to automotive and applications such as sensing and machine vision systems. Here, we report our recent achievements with a camera module based on an MOE lens. We have successfully designed and manufactured camera modules using a single MOE lens showing excellent performance compared to refractive lens counterparts. The design has a low f-number and extremely high relative illumination. Prototypes are prepared using e-beam lithography, whereas MOE lenses in mass production are manufactured using nanoimprint lithography. The characterization of the MOE lenses reveals full agreement with the simulated nominal design. Image artifacts can appear due to higher orders of diffraction if the MOE lenses are not designed and manufactured properly. To illustrate the promise for volume production, a tolerance analysis has been performed, where the system tolerance analysis shows yield versus performance. At the module level, a straylight study, including ghost image and finally, thermal stability has been analyzed. The tolerance and thermal analysis are not presented in this manuscript. These results show the advantages of using 'NILT's high-efficiency meta optical elements compared to traditional optical systems.
Wide aperture (50 mm), compact, and high-quality continuous focus tunable Gradient Refractive Index (GRIN) liquid crystal lenses
Amit K. Bhowmick, Afsoon Jamali, Douglas Bryant, et al.
Continuous tunable lenses have significant prospect to replace conventional bulky fixed power lens system. However, lightweight, fast response, large aperture (⪆1 cm) tunable lens system remained an active challenge in the field of adaptive optics. While many approaches have been reported so far, very few can be realized for practical application of optics that requires large aperture size tunable lenses. Gradient Refractive Index (GRIN) liquid crystal lenses are one of approach which gives good control over the continuous tunability, however, large aperture device suffers from very low switching speed. In this paper, without compromising the switching speed, we are reporting 5 cm aperture size GRIN liquid crystal based continuous tunable focus lens. Reported approach implements Fresnel lens like parabolic shaped segmented phase profile instead of continuous phase, which is obtained from segmented voltage distribution. The designed lens is flat, fast switching (⪅500 ms), thin (⪅ 2 mm), light weight (⪅ 10 gm), low voltage driven (⪅ 5 V), also tunable continuously between positive to negative power. Such compact system with good optical quality scopes for potential application in eyeglasses to solve presbyopia, accomodation-convergence mismatch issue in emerging head mounted display technology, and many other imaging systems.
Widely tunable large area thin liquid crystals lens
Javier Pereiro García, Manuel Caño-García, Xabier Quintana Arregui, et al.
Reconfigurable diffractive lenses manufactured in liquid crystal are presented. The lenses show an unprecedented performance in terms of active diameter and focal distance range when compared to any other transparent adaptive lens. The lenses are characterized by an active area free of electronic components, with a fill factor of 98% which combined with a low operating voltage (⪅10Vrms), open for applications ranging from eye contact lenses to space applications. The addressing of the liquid crystal is done exclusively from the periphery of the device. The lenses are based on tunable spiral diffractive lenses (SDL) for which the focal length may be changed by changing the topological charge, i.e. twist of the spiral in the lens. The twist in the resulting wavefront is eliminated by cascading two spiral plates with opposite twists emulating a conventional diffractive lens. The presented lenses have a tuning range from -2 to +2 diopters and an active diameter of 25mm.
Measurement of refractive index and liquid diffusion coefficient based on focal plane imaging method
Li Wei, Haifeng Gao, Haitao Zhou, et al.
Liquid-core cylindrical lens (LCL) is glued together by two cylindrical lenses, translucent liquid with refractive index n is injected into the liquid core, based on focal plane imaging method, the refractive index n has a one-to-one dependence on the focal length f of the LCL, n= f(n). Two kind of LCL, symmetrical liquid-core cylindrical lens (SLCL) and asymmetrical liquid-core cylindrical lens (ALCL) had been designed and fabricated, the refractive index measurement accuracy is superior to 0.0002 RIU. Based on the refractive index spatial measurement capability of ALCL, the equivalent refractive index thin layer movement method for rapidly and accurately measuring the diffusion coefficient D under the infinite dilution condition was applied to measure an aqueous CaCl2 solution at temperature of 303 K, and the result D were simulated and verified by ray tracing method. Comparing with the traditional method, this method has the advantages of visualization of diffusion process, strong anti-interference capability, rapid measurement, which can be widely used in medical, chemical, biological, environmental protection or other fields.
Simulation of Optical Systems
icon_mobile_dropdown
Accurate camera performance prediction using optical and imaging simulation pipeline for super wide-angle lens
Optical design process consists in minimizing aberrations using optimization methods. It relies on key performance indicators (KPIs), such as point spread function (PSF), Modulated transfer function (MTF), or relative illumination (RI) and spot sizes, that depend on lens elements aberrations. Their target values need to be defined -either for human or machine perception- at early stage of the design, which can be complex to do for challenging designs such as extended field of view. We developed an optical and imaging simulation pipeline able to render the effects of complex optical designs and image sensor on an initial aberration-free image. Extracting files from ray tracing software for simulating the PSF and sensor target information, the algorithm accurately renders off-axis aberrations with Zernike polynomials representation combined with noise contribution and relative illumination. The obtained image faithfully represents an optical system performance from the optics to the sensor component and we can then study the impact of additional aberration introduction.
A toolkit for multiscale optical system inverse-design
Optical system design is undergoing a transformational change with the increases in computational horsepower, cutting-edge algorithmic developments, and the advent of new nanofabrication technologies. Among the most exciting advances in recent memory are optical metasurfaces, which are patterned surfaces commonly realized through nanofabrication that can imbue optical engineers with expanded degrees of design freedom due to their ability to exploit the generalized form of Snell’s law. Through intelligent optimization and design, metasurfaces can be constructed which achieve arbitrary chromatic dispersion behaviors and unprecedented control over polarization that simply cannot be realized with conventional optical elements. However, designing high-performance metasurfaces requires the use of full-wave simulation tools and numerical optimization techniques which necessitate considerable computational resources. Moreover, while optical metasurfaces are moving towards millimeter and centimeter scale diameter lenses with advances in nanofabrication techniques, it is computationally infeasible to employ full-wave simulation tools directly to model optical systems that use such large size elements. Nevertheless, the size, weight, and power (SWaP) advantages afforded by optical metasurfaces make them a compelling choice for designers to consider in a number of applications, which are currently limited by bulky conventional optical solutions. Therefore, techniques that can rapidly model metasurfaces in conjunction with conventional optical elements such as lenses, mirrors, and prisms are highly desirable. In this presentation, we highlight a toolkit of custom solvers, design procedures, and powerful optimization algorithms that simplify and accelerate the development of hybrid optical systems with arbitrary combinations of conventional and metasurface elements.
Caustic produced by refractive conic surfaces
We study the formation of caustic produced by refraction through conic surfaces, considering a point source placed along the optical axis at arbitrary distances from the vertex of refracting surface. We demand that the optical surface is represented by a mathematical function, which is smooth, continuous, and derivable. We implement an exact ray trace to obtain a monoparametric equation that describes a family of refracted rays, which are propagated as a function of the angle of emission from the point source for each ray. Subsequently, by using the envelope’s method, we provide an analytical equation for the caustic surface as a function of all the parameters involved in the process of refraction. We analyze the paraxial approximation assuming a very small angle about the axis of the system. Additionally, we provide a formula, which describes the conditions for total internal reflection. Finally, we present the formation of caustic surfaces by considering a liquid polymer in a rotating vessel forming a paraboloid surface, also we present the caustic surface produced by the package of a Light Emitting Diode, to produce an uniform illumination pattern.
Challenges using data-driven methods and deep learning in optical engineering
Data driven approaches have proven very efficient in many vision tasks and are now used for optical parameters optimization in application-specific camera design. A neural network is trained to estimate images or image quality indicators from the optical characteristics. The complexity and entanglement of such optical parameters raise new challenges we investigate in the case of wide-angle systems. We highlight them by establishing a data-driven prediction model of the RMS spot size from the distortion using mathematical or AI-based methods.
A file sharing site for lens designs
Daniel J. Reiley, William Claff
A file sharing site for lens designs has been started at www.lens-designs.com. This site currently contains almost 2,000 optical models. Many engineering disciplines have built public libraries of useful, publicly-available content. For example, GITHUB1 has publicly-available software; GrabCAD2, 3DcontentCentral3, TurboSquid4 all offer mechanical engineering content such as solids files; TI, Analog, etc. offer reference designs for electronics engineers. Generally, these services aren’t just file repositories; they also offer collaboration, yielding more models, more refinement, more discussion, more community, and more to learn. Lens designers can also benefit from such design libraries. This paper explains the utility and structure of the site.
Modeling and Illumination
icon_mobile_dropdown
Light source modeling for UltraViolet-C Light-Emitting Diodes (UV-C LEDs) with aid of fluorescent film
We perform the mid-field model of a UV-C LED with an arranged wavelength of around 275 nm by comparing the 2-dimension (2-D) gray-level image captured by a monochromatic CMOS and the corresponding simulated irradiance pattern. Owing to UV-C light, we propose using a fluorescent film to absorb UV-C light and re-emit light at a longer wavelength so that the 2-D gray level image can be captured. The calibration to approach the corrected gray level of image is presented. Consequently, we obtain the precise mid-field light source model. Moreover, the model is also applied for dome lens design and then compares the optical behavior with fabricated samples in measurement to evaluate its validity.
Achieving multiple beam patterns using 3-D printable lens by altering the positioning of LEDs
As lighting has diversified across many applications, optical designers have been challenged to produce application-specific optical systems. For an instance where multiple beam distributions are required in an application, instead of making individual lenses catering to different beam shapes, it would be beneficial to create a single optic that can be used with different LED source positioning. Hence, this study proposes a method of positioning LEDs in a fixture to achieve multiple beam patterns using a fixed lens design. Through ray-tracing analysis, we showed that different beam distributions could be obtained by changing the LED position in a refractive lens array. The experimental study was conducted with a 3D-printed lens to validate the model. The results confirm the possibility of creating a single fixed lens to achieve multiple beam distributions via different LED positioning. The proposed novel method can replace the expensive and cumbersome process of developing separate lenses for each beam distribution. Further, our experimental results can guide fixture manufacturers on the use of 3D-printed optics for lighting applications.
An LED metalens for uniform illumination
We develop a design method of flat optics for illumination. We describe a metalens design method for uniform illumination based on the ray mapping algorithm between a point source and a target. Based on metasurface refraction equation and a suitable ray mapping, a first order differential equation that represents the characteristics of the desired illumination distribution is presented. The metalens phase profile for uniform illumination is obtained by solving this simple equation. The results show that we can get a metalens for uniform illumination with a point source, for example a small light-emitting diode (LED).
Adjustable mini-LED array applied to low/high beam meet the K-mark regulation
In this study, we use 30 mini-LED arrays as the light source of the bike lamp. A single reflector with 68 segments to project vehicle low beam and high beam with the use of a GaN-based mini-LED matrix, which is a 30 LED dies array. The design of the reflector is based on light field technology in considering etendue from the light source across the segments. The group of the segments with smaller etendue from the LED dies in the bottom 2 rows are used to project low beams. When the other LED dies are turned on, the reflector will project light upward and form the high beam. The selection of the turn-on LED dies in the mini-LED matrix can adjust the width of the illumination pattern so that an adaptive low/high beam can be performed.
Integration of Optical Designs into Complete Instruments
icon_mobile_dropdown
An endoscopic lens with internal focusing
Henning Rehn, Hans Forrer, Christian Mehne, et al.
We report optical and optomechanical design of a new endoscopic system for the urinary bladder. On the basis of the specification, key requirements of the optics are derived. The required high resolution goes hand in hand with a depth of field much smaller than the intended object distance range and raises the need for image focusing. Such a focus mechanism was realized in the small endoscope tip volume with the help of smart memory alloy wires and a matching optical and mechanical design. MTF measurements and practical tests demonstrate a proper function of a prototype of the device.
A hybrid HCPV system designed for multi functions
Chi Sun, Chi Shou Wu, Yong-Sheng Lin, et al.
In this study, we first focus on the study of the mass-productive Fresnel lens in the HCPV to calculate the amount of the leakage light. Then we will study the leakage light by the natural factor, such as clear sky, light cloud, medium cloud, and heavy cloud. Finally, we will summarize the characteristic of the light leakage in HCPV in considering the engineering and natural factors.
Design of projection-based augmented reality system using holographic screen display
Holographic display elements (HOEs) with a high diffraction efficiency and size enlargement have been developed since 2019. To achieve high brightness and low haze, unprecedented optical systems have been proposed with a uniform chief ray angle of 0° in the x-section and 70° in the y-section of the HOEs. A 360° cylindrical holographic screen display (CHSD) was obtained by providing a large tilt to the surface shape near the optical axis. This was done using a first-order odd aspherical coefficient for the light flux from a refractive optical system (RO). A flat holographic screen display (FHSD) is a compact, high-performance display that uses three decentered and tilted freeform mirrors to route light flux from the RO in a ball-like form. Prototyping also proposes the possibility of an augmented reality system that takes advantage of the high transparency. The design for further miniaturization while maintaining optical performance was also discussed, in which the size of the first mirror was reduced by reducing the half-field angle of the RO to approximately 6°. Furthermore, by increasing the negative power of the second mirror, the small size could be maintained. The size of the last mirror was dependent on the screen size and could not be reduced. By laying down the posture of this mirror, we were able to halve the size reduction in the vertical direction. In this paper, lens designs for CHSDs and FHSDs are reported. The potential of this display is also discussed.
Generative design and digital manufacturing: using AI and robots to build lightweight instrument structures
Digital Engineering technologies are transforming long-stagnant development processes by applying the tremendous advancements in Information Technology (IT) to classical engineering tasks such as design, analysis, and fabrication of space-flight instrument structures. Generative Design leverages developments in Artificial Intelligence (AI) and Cloud computing to enable a paradigm shift in the design process, allowing the engineer to focus on defining the requirements and objectives of the design while AI generates optimized designs which comply with the input requirements. Digital Manufacturing allows these complex lightweight designs to be efficiently manufactured by directly fabricating from the resulting 3D models. The development of these two Digital Engineering technologies realizes significant mass savings while simultaneously reducing structure development time from months to days. This paper describes the development of the Evolved Structures process applying these technologies to spaceflight optical instrument structures including an example demonstrating greater than 10x reduction in development time/cost and greater than 3x improvement in structural performance.
Theory and Applications II
icon_mobile_dropdown
Optical design process of a human eye inspired lens
Guillaume Allain, Simon Thibault
Bio-inspired optical design can be described as a conscious decision in the design process to take inspiration from physical adaptation that were brought up by natural selection. The usual goal is to introduce non-conventional techniques or material in order to achieve better performance or novel applications. However, when the target is to imitate closely the form-factor, appearance and optical properties of a biological system, new requirements are added to the design process and new problems arises. In this paper, we will expose the design of an optical system that draws most requirements from both the optical properties and the form-factor of the human eye. However, contrary to human eye models, the main requirements for this project is to make a realistic design which can be assembled as a prototype. The design process will be laid out, by firstly introducing system requirements and various performance targets that comes from the bio-inspired design. The constraints associated with using entrance pupil’s appearance as a requirement will be presented. This paper will also specifically be looking at distortion as a solution for modulating resolution throughout the field of view and as a tool to aid in those novel problems.
Realizing low-distortion in wide-angle lens with freeform optics technique
Zhenfeng Zhuang, Jocelyn Parent, Patrice Roulet, et al.
Distortion is one major shortcoming of conventional wide-angle lens. The correction of distortion can maximize field of view in a wide-angle lens and benefit natural scenes. In this paper, we propose a compact wide-angle lens utilizing freeform surfaces to address the shortcoming. The design approaches, including the starting point selection, freeform surface conversion scheme, and system optimization, are discussed in detail. Moreover, freeform diagnostic tools are developed aiming to facilitate system optimization and visualize the critical aspects of optical performance. The simulation results are demonstrated and discussed. Analysis results demonstrate that the design strategies proposed in this paper have been shown to be effective in reducing distortion as well as improving optical performance. We envision that the proposed design schemes will have a positive effect on research and application values for wide angle lens system.
TIR metalens simulation
Edgar Dávila, J. C. Basilio-Ortiz, Ivan Moreno
Current advances in metalenses are leading to the development of new compact optical systems, mainly in imaging applications. Here, we focus the study of metalenses in nonimaging optics applications. In this work we present the study and design of a total internal reflection (TIR) metalens by using finite difference time domain (FDTD) electromagnetic simulations. The TIR metalens is configured by both a metalens and a metamirror on a transparent plate, and as source a light emitting diode (LED) is used. We make an analysis of the efficiency of the proposed configuration by using FDTD simulations.
Poster Session
icon_mobile_dropdown
Method for designing optical systems from the off-the-shelf optical components
Lev Ryzhikov
Several off-the-shelf optical lenses and lens components are available for use in the design of new optical systems. But there isn’t a clear methodology on how effective there can be in a real optical device. It should be noted that the use of standard optical elements reduces the cost of the optical device, which is especially important for mass production. Ease and speed of replacement are also important parameters for the usability of standard optical elements. That is why the extensive use of purchased optical elements in optical devices will simplify their operation and improve the convenience of maintenance. Selecting purchased optical components of an optical circuit is not an easy task and requires certain skills. The main problem is that the optical design stage is divided into two parts. The first part is the creation of an optical circuit from non-standard (custom) optical components with optical characteristics close to cataloging lenses. The second part is to adjust the position of the optical component to satisfy specification requirements. This process sometimes required several iterations. For the process of fitting distances in an optical system to be successful, it is necessary to take into account the properties of optical glasses such as refractive index and dispersion when choosing lens components, in addition to their focal lengths and geometrical dimensions. It should be noted that in the catalogs of optical components there are optical parameters of lenses, and also glass parameters of the lens. This is essential information for lens designers to substitution the custom optical element for the off-the-shelf lens. Problems that arise with such a replacement are based on a limited number of standard lenses and lens components. To get comfortable for replacement, the custom lenses components must be modified (adjusted) so that optical parameters will be close enough to the parameters of the catalog lenses other words during the custom lenses optimization process the lens shapes and an optical power should be fully matched (in the ideal case) with catalog lenses data. Method how to effectively get this match will be discussed below.
Multichannel-optical prism
Lev Ryzhikov
Currently, many optical tests required simultaneous measurement values of various technological or metrological parameters. This demand primarily applies to pieces or parts of products that are under variable load during operation. These technological measurements primarily relate to production and metrological works. Examples include optical testing of deformations of parts (e.g., plates) under variable load, shifts of various components of high-precision equipment, and, of course, various metrological measurements of high-precision equipment, such as lithographic machines and different types of measuring and control devices. Simultaneous measurement of the same parameter in different parts of the product allows for to determination of the error (e.g., deformation or alignment error) in object position during operation. Observation and analysis of the position of specific points on the object allow one to judge deviations both in position and deformation of the measured surface. The proposed multichannel optical prism can simultaneously observe several points located on the different parts of the object, as well as monitor their movements and deformations in working conditions. This information allows you to determine the operating conditions of various structural elements during real operation. The multichannel prism should be built into the optical circuit of the measuring (metrological) device. The use of prisms of this type allows simultaneous observation of the movement (deformation) of various parts of the observed objects. Some examples of such kinds of optical devices with a build-in multichannel prism will be discussed below.
Design of an expander lens for an MWIR zoom camera using the third-order aberration analysis
This study presents the methods for designing an expander lens for an MWIR zoom lens through the third-order aberration analysis and evaluating the optical zoom system. This expander lens is used to enlarge the focal lengths of an original main zoom lens two times, which unfortunately doubles the aperture size of the expander lens elements. Thus, this extended apertures significantly generate the aberrations of a zoom system. To solve the problem, an expander lens has been designed using the third-order aberration analysis numerically. Since an MWIR optical system uses a cooled detector, this zoom system should be designed to eliminate the narcissus effect. Using this design approach, we efficiently obtain an expander lens for an MWIR zoom system satisfying the current requirements.
Changing field of view by applying voltage difference
Dual field of view optical systems provide search, detect and observation abilities with wide and narrow field of views. These systems provide dual field of view by changing the effective focal length with moving a lens or lens group mechanically to exact positions. In this paper, previously proposed methodology is used to change effective focal length without any mechanical movement. This methodology relies on ionization of fluid with voltage difference to change the refractive index which is patented in 2022.
Optical design of dual mode imaging infrared system in MWIR and LWIR spectral bands
Optimization process is the one of the most crucial part of optical design due to it’s including weight, size and performance parameters. Current developments in optical and electronical technology reduce the size and weight of these systems and improve image performance. In this study, optical design of small diameter dual mode imaging infrared system will be summarized. Optical design is including prisms to provide wide field of regard which are rotated in roll axis to scan area. Optical design is also including a filter to split long-wave infrared and mid-wave infrared spectrums from each other. At the end optical design results and analysis will be given.