We provide analytic formulas for fews aspheric terms either plano-convex or convex-plano aspheric lenses. These formulas are obtained considering an expansion in Taylor's series from exact caustic equation produce...
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ISBN:
(纸本)9780819496911
We provide analytic formulas for fews aspheric terms either plano-convex or convex-plano aspheric lenses. These formulas are obtained considering an expansion in Taylor's series from exact caustic equation produced by aspheric lenses. A comparison between our method and numerical methods of design are presented, showing a well agreement in order to reduce the spherical aberration.
An afocal optical system designed to be attached to a conical optical beam deflector is discussed The conical beam deflector generates a collimated optical beam that rotates along a cone-shaped trajectory in space. Th...
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ISBN:
(纸本)0819422517
An afocal optical system designed to be attached to a conical optical beam deflector is discussed The conical beam deflector generates a collimated optical beam that rotates along a cone-shaped trajectory in space. This output beam is then fed to the afocal attachment, a telescope, designed to tailor the beam characteristics to suit a particular application. For many applications, the afocal attachment functions as a beam expander and modifies three characteristics of the input beam. First, it expands the input beam diameter to an acceptable level. Then, it inevitably reduces the apex cone angle of the beam due to the inherent property of a telescope. Third, the stationary plane, the plane where the apex of the cone resides, is magnified and transferred to the conjugate image plane.
The paper presents the mathematical technique for calculation of the diffraction depth of focus of an optical system of a widefield microscope. The proposed technique applies the Rayleigh criterion based on evaluation...
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ISBN:
(纸本)9780819482822
The paper presents the mathematical technique for calculation of the diffraction depth of focus of an optical system of a widefield microscope. The proposed technique applies the Rayleigh criterion based on evaluation of the wave aberration appeared due to defocus in a high aperture optical system. The maximal value of a linear approximation of the defocus wave aberration is used to define the depth of focus. It is proven that in optical systems with numerical aperture higher than 0.5 have the diffraction depth of focus 25 - 40% smaller than the widely known formula defines. This fact is important for implementation of autofocus and digital focus extension algorithms. The non-sophisticated formula for calculation of the depth of focus is proposed. The results of experimental measurements of the depth of focus are presented and discussed.
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 this study, a low glare and high-efficient tunnel lighting design which consists of a cluster light-emitting diode and a free-form lens is presented. Most of the energy emitted from the proposed luminaire is transm...
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ISBN:
(纸本)9781628412192
In this study, a low glare and high-efficient tunnel lighting design which consists of a cluster light-emitting diode and a free-form lens is presented. Most of the energy emitted from the proposed luminaire is transmitted onto the surface of the road in front of drivers, and the probability that the energy is emitted directly into drivers' eyes is low. Compared with traditional fluorescent lamps, the proposed luminaire, of which the optical utilization factor, optical efficiency, and uniformity are, respectively, 44%, 92.5%, and 0.72, performs favorably in traffic safety, energy saving, and glare reduction.
We derive a closed-form expression for the entrance pupil of the on-axis stigmatic singlet lens, and discuss its performance for a variety of conditions, including positive or negative indices of refraction, and diffe...
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ISBN:
(数字)9781510637719
ISBN:
(纸本)9781510637719
We derive a closed-form expression for the entrance pupil of the on-axis stigmatic singlet lens, and discuss its performance for a variety of conditions, including positive or negative indices of refraction, and different positions of the object and the image.
Many fundamental astronomical problems need much higher resolution than is afforded by atmospheric visibility or the diffraction limit of even the largest telescope being planned. The only way to meet these demands is...
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ISBN:
(纸本)0819403954
Many fundamental astronomical problems need much higher resolution than is afforded by atmospheric visibility or the diffraction limit of even the largest telescope being planned. The only way to meet these demands is by a distributed array of telescopes similar to those used in radio astronomy, or the long baseline stellar interferometry. China is planning to build a small-aperture long- baseline stellar optical interferometer for three purposes. One purpose is to clear up some problems before building a large and expensive interferometer. The second is to measure angular diameters of stars and angular distances between double stars. The third is to modify it for astrometry use in the future. In this paper, the design tolerance and specifications of the interferometer are discussed based on the astronomical requirements.
In this paper, combining refractive and diffractive effects, a new kind of infrared lenses with wavelength 10.6 mu m was designed and produced for CO2 laser material processing. This refractive-diffractive lens (RDL) ...
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ISBN:
(纸本)0819422517
In this paper, combining refractive and diffractive effects, a new kind of infrared lenses with wavelength 10.6 mu m was designed and produced for CO2 laser material processing. This refractive-diffractive lens (RDL) converts a CO2 laser beam into the rectangular shape with light intensity distribution in the concave shape at x-direction. A method which employs input aperture division and geometrical transformation technique for obtaining a better initial phase distribution of the iteration is presented. The experimental results show that the desired shape of the output light beam was obtained with a high efficiency in energy utilization.
Infrared Focal Plane Array (FPA) sensors are commonly tested using various means of scene generation. At the Arnold engineering Development Center a Direct Write Scene Generator (DWSG) is being developed. The DWSG pro...
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ISBN:
(纸本)0819415871
Infrared Focal Plane Array (FPA) sensors are commonly tested using various means of scene generation. At the Arnold engineering Development Center a Direct Write Scene Generator (DWSG) is being developed. The DWSG projects the scene onto the focal plane array by scanning a rake of beams across the sensor. The rake consists of up to 256 synchronous beams generated by passing a single laser beam through an acousto-optic deflector (AOD). A complex radio frequency signal input into the AOD diffracts the laser beam into multiple beams. Each pixel of the focal plane is illuminated by one of the beams in the rake. The Direct Write Scene Generator is being designed to test a focal plane area as large as a 512 X 512 pixel array. Scan optics focus an expanded laser beam to a spot smaller than the focal plane pixel pitch over the entire test area. Several optical configurations and multiple AODs are needed to achieve the test requirements at various wavelengths. Some important considerations in the opticaldesign are spot size, crosstalk, and background radiation.
A refractive astigmatic lens is employed to generate a focus error signal (FES) for servo control in general optical pickup. In this paper, a diffractive optical element (DOE) is designed to implement optical function...
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ISBN:
(纸本)9780819468154
A refractive astigmatic lens is employed to generate a focus error signal (FES) for servo control in general optical pickup. In this paper, a diffractive optical element (DOE) is designed to implement optical functions of astigmatic focusing for a MEMS-based miniature optical pickup at 650nm wavelength. We present a diffractive astigmatic lens with its internal zones and external zones quantized into four, two phase levels, respectively based on fabrication consideration. The optical simulation based on scalar diffraction theory shows the efficiency of this quantized lens for astigmatic focusing and a comparison of the FES in the optical pickup system has been plotted.
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