Consumers nowadays have a higher expectation on cameras beyond the function of taking photos or videos. In the early years, the applications of cameras with lenses were, however, very restricted. A new generation of s...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
Consumers nowadays have a higher expectation on cameras beyond the function of taking photos or videos. In the early years, the applications of cameras with lenses were, however, very restricted. A new generation of super wide-angle lenses capture the user's surroundings in full 360 degrees, allowing the user's friends or families to step inside our universe and experience it, live. However, for such wide angle lens coverage, the relative illumination of the lens must take the vector nature of the light into account. Consequently, the polarization of light becomes a critical parameter. Custom coatings are commonly spread on the lens surface to avoid light transmission polarization falloff. But for consumer applications, complex coating is not a practical solution because it raises cost. In this paper, we present how to take care of the polarization during the design and analysis of the lensdesign. Additionally, design tips are proposed to suppress the polarization impact.
The design of high quality very wide-angle opticalsystems (FFOV > 100 degrees) relies on distortion to obtain a sufficient resolution at, usually, the center of the field of view. Using distortion shape as a param...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
The design of high quality very wide-angle opticalsystems (FFOV > 100 degrees) relies on distortion to obtain a sufficient resolution at, usually, the center of the field of view. Using distortion shape as a parameter during optimization to reach a magnification target is a common technique to achieve optical foveation during the lensdesign process. This method allows resolution enhancement at selected parts of the field of view since less care is given to parts of the image that are deemed less important. However, accurate control of distortion can be a challenge during opticaldesign since the standard aspherics polynomials don't correlate directly to image magnification. This may in fact slow down optimization since the merit function is much less optimized to approach a solution. In this paper, we address this problem by presenting a method to simplify distortion control during the opticaldesign phase. To achieve this, the use of orthogonal polynomials is used for defining the optical surface shape and will then be used to compare the height of the image plane at a given field of view. We show that in the case of simple and paraxial system, this process is orthogonal and achieve a solution in a single optimization step. We will finally discuss the limits of this method and how it applies to modern lensdesign problems.
In the past two decades, to realize high resolutions and low distortions while miniaturizing opticalsystems, various ultrashort throw lenses (USTs) have been proposed. In this work, ultrashort throw lenses with a cat...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
In the past two decades, to realize high resolutions and low distortions while miniaturizing opticalsystems, various ultrashort throw lenses (USTs) have been proposed. In this work, ultrashort throw lenses with a catadioptric relay (USTCRs) with rotational symmetry are proposed to provide the solution. First, the initial design method of the USTCR and the optimized design solution are presented. Although this optical system with a throw ratio of 0.26:1 has resolutions and distortions equivalent to those of conventional UST with one aspherical mirror, the depth of focus (DOF) on the panel side becomes 1.31 times deeper with appropriate corrections of the field curvature. The total length of the lens is reduced to 0.89 times, the area of the main mirror is reduced to 0.22 times, and the number of lenses is reduced from 13 to 9 elements. Based on these results, several opticaldesigns for USTCR have been tried and an opticaldesign with robustness has been proposed. By optimizing the power of each lens group, the decenter sensitivity improved to 0.46 times for parallel decenter and 0.55 times for tilt decenter. By optimizing glass materials, the shift of focal plane can be suppressed to 0.56 times when the temperature increases by 30 degrees C. An USTCR suited for a curved screen has also been proposed. By introducing appropriate constraints that correct distortions, high resolutions and low distortions have been realized while maintaining a wide angle of view. USTCRs suited for various curved screens are currently underway.
The work presented here shows a compact lens system that demonstrates improved imaging quality performance while focusing on as-built performance and design for manufacturing. Using Zemax, we consider an approach for ...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
The work presented here shows a compact lens system that demonstrates improved imaging quality performance while focusing on as-built performance and design for manufacturing. Using Zemax, we consider an approach for optimizing for as-built performance and incorporate the approach into the design process for a mobile phone camera. The optimized design consists of 6 plastic aspheric lenses, an infrared glass filter, and a 12 MP CMOS image sensor. The optical system demonstrates high-resolution imaging and has a field-of-view of 87.6 degrees, an F-number of 2.0, a maximum distortion of less than 2.5%, and a total track length of 6.630 mm.
In missile applications, new counter measure methods are getting more complex. To discriminate and detect counter measure and to understand target signature from scene is getting harder. Because of all that concerns, ...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
In missile applications, new counter measure methods are getting more complex. To discriminate and detect counter measure and to understand target signature from scene is getting harder. Because of all that concerns, using triple-mode seeker for a system solution is a good solution for system total performance. By this way, tri-different wavelength could be used for same system and same scene. In this study, triple mode system's opticaldesigns have been made for mid-wave infra-red imaging, long-wave infra-red imaging and short-wave infrared imaging. opticaldesigns performances have been illustrated in simulation results. Finally, conceptual design of triple mode seeker will be summarized.
Data-driven approaches to lensdesign have only recently begun to emerge. One particular way in which machine learning, and more particularly deep learning, was applied to lensdesign was by smoothly extrapolating fro...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
Data-driven approaches to lensdesign have only recently begun to emerge. One particular way in which machine learning, and more particularly deep learning, was applied to lensdesign was by smoothly extrapolating from lensdesign databases to provide high-quality starting points for lensdesigners. This mechanism is used by the web application lensNet (which will be publicly available shortly) whose goal is to provide high-quality starting points that are tailored to the desired specifications, namely the effective focal length, f-number and half field of view. Here, we evaluate more thoroughly the designs that are inferred by lensNet and its underlying deep neural network. We provide a global quantitative assessment of the viability of the designs as well as a more targeted comparison among specific design families such as Cooke triplets and Double-Gauss lenses between expert-designed lenses and their automatically inferred counterparts.
In this paper we examine the third-order aberrations of the "generalized Offner" family of designs comprising three concentric mirrors, with the first and third mirrors being not necessarily identical in rad...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
In this paper we examine the third-order aberrations of the "generalized Offner" family of designs comprising three concentric mirrors, with the first and third mirrors being not necessarily identical in radius and including the possibility that the object might be displaced from the common centers of curvature. We develop analytic expressions relating the first-order and third-order properties of the system to the radii of the three mirrors and to the object distance. Although one might expect a ring-field system to be relatively tolerant of field curvature, we show that the Petzval Sum affects the other aberrations in an extraordinary manner.
This paper proposes the design of an anastigmatic three-mirror telescope using freeform surfaces for the correction of spherical aberration, coma, astigmatism, and field curvature, allowing a wide field of view (FOV) ...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
This paper proposes the design of an anastigmatic three-mirror telescope using freeform surfaces for the correction of spherical aberration, coma, astigmatism, and field curvature, allowing a wide field of view (FOV) and high resolution. For the structure of this telescope, it is proposed to use only two optical elements where the primary and tertiary mirrors are integrated into an only optical element and the secondary mirror in the other, thus achieving a considerable reduction in the difficulty of alignment and assembly. To achieve a high performance of the telescope, the system was decentered (off-axis design), avoiding the loss of energy due to the obscuration of the M-2 in the on-axis system. In addition, to solve the difficult access to the focus.
In this paper, different opticaldesigns, which are composed of different LWIR optical materials, are utilized for passive athermalization and their performance in athermalization are analyzed. The opticaldesigns are...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
In this paper, different opticaldesigns, which are composed of different LWIR optical materials, are utilized for passive athermalization and their performance in athermalization are analyzed. The opticaldesigns are carried out by preserving the athermal property as well as keeping the image quality at higher levels within the working temperature between -40 degrees C and +60 degrees C. Our designs consist of two different infrared optical elements to maintain the focus positions as stable as possible within the working temperature. The passive athermalization process begins with the calculation of athermalization conditions of candidate material properties. By taking into account these conditions, athermal material pairs are chosen. The opticaldesign begins with an optimization process using paraxial optics. In order to reduce aberrations such as coma, astigmatism, spherical and chromatic, 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.
In conventional imaging, the information transfer from the object to the image plane is accomplished either with the help of a traditional lens that performs a one-to-one mapping or an unconventional lens that perform...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
In conventional imaging, the information transfer from the object to the image plane is accomplished either with the help of a traditional lens that performs a one-to-one mapping or an unconventional lens that performs a one-to-many mapping. In the first case, the image is formed directly, whereas in the second case, the image is formed after a computation. The conventional lens approach is preferred in most cases due to the high signal-to-noise ratio achievable at each image pixel. By appealing to the fact that for most of the imaging applications, it is only the intensity, which is measured by the detector, the phase of the field in the image or focal plane is a free parameter, something that comes from the inverse diffraction transform. Therefore, it is easy to visualize that this phase of the plane wave after it transmits the lens can have multiple forms. Hence, the final choice can be made based upon specific application tailored requirements like achromaticity, depth-of-focus, wide-angle imaging, etc. This concept was exploited to design an achromatic MDL via inverse design across almost the entire electromagnetic spectrum (lambda = 450 nm to 15 mu m). Furthermore, a MDL with a Field Of View (FOV) up to 50 degrees for wide-angle imaging as well as a MDL to enable an extreme Depth of Focus (EDOF) imaging of up to 6 m in the NIR were also designed.
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