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.
Refractive optics has evolved and incorporated new elements in optical systems every day, such as conventional lenses, tunable lenses, GRIN lenses, diffractive lenses, intraocular lenses, etc. Some of these elements a...
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ISBN:
(纸本)9781628417449
Refractive optics has evolved and incorporated new elements in optical systems every day, such as conventional lenses, tunable lenses, GRIN lenses, diffractive lenses, intraocular lenses, etc. Some of these elements are reported in the literature together with different proposed models of the human eye. In this work, optical properties of some of these lenses will be studied, and simulations of their behavior will be done in order to analyze which one is better for imaging process. Such lenses will be incorporated in an optical system that mimics the human eye behavior. Analysis and obtained results are reported, as well as the proposed optical system. Finally, we present the conclusions of the work.
A new way to evaluate the diffraction efficiency of the diffractive optical element (DOE), which serves as an aberration corrector in an infrared hybrid optical system, is proposed. The directly measured ensquared ene...
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ISBN:
(纸本)0819454613
A new way to evaluate the diffraction efficiency of the diffractive optical element (DOE), which serves as an aberration corrector in an infrared hybrid optical system, is proposed. The directly measured ensquared energy of the hybrid optical system is obtained through an experimental test. Then, the actual line spread function (LSF) of the system under test is measured, and the point spread function (PSF) is calculated from LSF based on the symmetric property of the system. The PSF is used to calculate the so-called derived ensquared energy. The ratio of the directly measured and the derived ensquared energy, defined as the diffraction efficiency of the DOE, represents the fraction of the energy focused onto the image point over the total input energy on the image plane, because the energy loss is caused by the scattering from the DOE corrector. The hybrid optical system, experimental setup, evaluation procedure, and the final results will be presented.
The design & tolerancing of an optical testing system (OTS) presents a unique set of challenges not generally encountered during the typical opticaldesign process. The authors have spent the past six years develo...
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ISBN:
(纸本)0819454613
The design & tolerancing of an optical testing system (OTS) presents a unique set of challenges not generally encountered during the typical opticaldesign process. The authors have spent the past six years developing and using a series of optical systems designed to measure the surface figure & radius-of-curvature of various ultra-lightweight mirrors at 30 K. These mirrors were part of a technology development program to support NASA's James Webb Space Telescope (JWST). The design of these systems required consideration of the following: (i) potentially large figure errors in the test mirror (due to gravity sag & cryo-distortion), (ii) cryo-shrinkage of the aperture and radius-of-curvature, (iii) figure changes due to the use of mirror actuators, and (iv) vibration between the OTS & the test mirror. In addition, an exhaustive tolerancing process was required for each system in order to reach a set of alignment tolerances that were achievable using the equipment available and within the test environment. The authors found many aspects of the OTS design process to be significantly different from the norm;at the same time, however, viewing the process as a typical opticaldesign problem often-times brought clarification. This paper will describe both the differences and the similarities observed between the design of an OTS as opposed to a traditional imaging system.
The diffractive optical element (DOE) is always modeled as an ideal pure diffractive clement which neglects the refractive dispersion of the clement's material. In this paper, a new model of the diffractive optica...
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ISBN:
(纸本)9780819472809
The diffractive optical element (DOE) is always modeled as an ideal pure diffractive clement which neglects the refractive dispersion of the clement's material. In this paper, a new model of the diffractive optical element is proposed, in which the effect of the refractive dispersion of the DOE's material is considered. The new model is explained and compared with standard diffraction-order expansion with the help of a hybrid system example. The analytical results show that the new model has an important meaning for the exact analysis of the hybrid refractive-diffractive optical system.
We have designed a light-guide for lighting applications, including automotive headlamps. The light-guide is designed based on a free-form slab. Our intention has been to optimize the design for creating legal pattern...
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ISBN:
(数字)9781510620629
ISBN:
(纸本)9781510620629
We have designed a light-guide for lighting applications, including automotive headlamps. The light-guide is designed based on a free-form slab. Our intention has been to optimize the design for creating legal patterns. One of our objectives has been to investigate how the changes in the shape of the freeform light-guide affects the light pattern, and how the light source geometry affects the design. For prototyping purpose, we use a particular polymer that exhibits optical performance close to acrylic (PMMA).
We present a theoretical method which makes it possible to analyze 3-D integrated optical waveguides with arbitrary refractive index profiles. With this method it is easy to obtain effective indexes, propagation const...
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We discuss the requirements on design and production regarding geometric and chromatic aberrations for objectives used in 4Pi confocal microscopy. We show that even the selection of a category 1/1 glass will not autom...
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ISBN:
(纸本)0819441554
We discuss the requirements on design and production regarding geometric and chromatic aberrations for objectives used in 4Pi confocal microscopy. We show that even the selection of a category 1/1 glass will not automatically assure that these requirements are met. due to residual variations in the Abbe number nu within the manufacturers tolerances. Consequently, the opticaldesign has to take into consideration the possibility of balancing chromatic aberrations by varying selected air spacings in the final assembly of each individual objective. We also demonstrate. that for analyzing the influence of aberrations on the intensity distribution along the optical axis. a scalar diffraction theory is still applicable and very useful.
The properties of optical surfaces generated by diffraction are studied analyzing the changes in the curvature function of the boundary condition. The study leads to establish a classification for the optical fields a...
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ISBN:
(数字)9781510602861
ISBN:
(纸本)9781510602854;9781510602861
The properties of optical surfaces generated by diffraction are studied analyzing the changes in the curvature function of the boundary condition. The study leads to establish a classification for the optical fields as elliptical, hyperbolical or parabolic. The elliptical regions are separated from hyperbolic regions by a region of parabolic type, which corresponds to optical focusing regions. The main result of the analysis leads us to describe and to control bifurcations and vortices effects allowing to geometrize and to control the topological properties of the optical field. For this feature is important to control the geometry of the parabolic region, obtained by controlling the curvature function in the boundary condition. The model is implemented experimentally applying a linear transformation in transmittances of zone plate type. The experimental results corroborate the theoretical predictions
Studies on adaptive lenses, which are formed of two transparent elastic surfaces and have a transparent liquid medium between them, have focused mostly on the characterization, analysis and optical performance of the ...
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ISBN:
(纸本)9780819468154
Studies on adaptive lenses, which are formed of two transparent elastic surfaces and have a transparent liquid medium between them, have focused mostly on the characterization, analysis and optical performance of the proposed lenses. No attention, however, has been given to the mechanical design that would allow the conception of a user-friendly functional mounting that is adaptable to conventional optical systems. This work, therefore, presents the design and manufacturing processes of the mounting for a 20 mm diameter biconvex adaptive lens. It also presents an analysis of the membranes used as elastic surfaces and the images formation of the proposed lens.
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