scholarly journals The Manufacturing of a Multi-surface Monolithic Telescope with Freeform Surfaces

2019 ◽  
Vol 215 ◽  
pp. 06004
Author(s):  
Todd Blalock ◽  
Brian Myer ◽  
Brittany Cox ◽  
Jessica Nelson
Keyword(s):  
Mechanical Stability ◽  
Optical Systems ◽  
Optical Performance ◽  
Freeform Surfaces ◽  
Optical Surfaces ◽  
Spherical Surfaces

Monolithic multi-surface telescopes combined with freeform optical surfaces provide improvements in optical performance in a smaller footprint as compared to systems with spherical surfaces, while providing superior mechanical stability to traditional telescope assemblies. Three different monolithic telescope concepts, in different configurations and optical performance were produced as proof of concepts. The results of the telescopes are presented as well as the unique manufacturing and testing challenges to produce these monolithic optical systems.

Optimization of freeform surfaces using intelligent deformation techniques for LED applications

2018 ◽  
Vol 7 (1-2) ◽  
pp. 67-80
Author(s):  
Annie Shalom Isaac ◽  
Cornelius Neumann
Keyword(s):  
Optimization Technique ◽  
Optical Performance ◽  
Optical Surface ◽  
Freeform Surfaces ◽  
Street Lighting ◽  
B Spline ◽  
Spline Surfaces ◽  
Freeform Deformation ◽  
Indirect Technique ◽  
Selection Of

AbstractFor many years, optical designers have great interests in designing efficient optimization algorithms to bring significant improvement to their initial design. However, the optimization is limited due to a large number of parameters present in the Non-uniform Rationaly b-Spline Surfaces. This limitation was overcome by an indirect technique known as optimization using freeform deformation (FFD). In this approach, the optical surface is placed inside a cubical grid. The vertices of this grid are modified, which deforms the underlying optical surface during the optimization. One of the challenges in this technique is the selection of appropriate vertices of the cubical grid. This is because these vertices share no relationship with the optical performance. When irrelevant vertices are selected, the computational complexity increases. Moreover, the surfaces created by them are not always feasible to manufacture, which is the same problem faced in any optimization technique while creating freeform surfaces. Therefore, this research addresses these two important issues and provides feasible design techniques to solve them. Finally, the proposed techniques are validated using two different illumination examples: street lighting lens and stop lamp for automobiles.

Development of Silicon Carbide Substrates for Aerospace Applications

2012 ◽  
Vol 1373 ◽  
Author(s):  
Antonio J. Abdalla ◽  
Álvaro J. Damião ◽  
Elson Campos ◽  
Jerusa G.A. Santana ◽  
Marcelo C. Vicentini ◽  
...  
Keyword(s):  
Organic Material ◽  
Mechanical Tests ◽  
Argon Atmosphere ◽  
Optical Systems ◽  
High Tech ◽  
Laser Confocal Microscopy ◽  
Optical Surfaces ◽  
Aerospace Applications ◽  
Sintering Additive ◽  
National Boundaries

ABSTRACTPayload and high-tech are important characteristics when the goals are aerospace applications. The development of the technologies associated to these applications has interests that transcend national boundaries and are of strategic importance to the nations. Ultra lightweight mirrors, supports and structures for optical systems are important part of this subject. This paper reports the development of SiC substrates, obtained by pressing, to be applied on embedded precision reflective optics. Different SiC granulometries, having YAG as sintering additive, were processed by: ball milling, drying and deagglomeration, sift, uniaxial and isostatic pressing, and, finally, argon atmosphere sintering at 1900°C. Different porosities were obtained according to the amount of organic material added. Into one side of the samples pellets of organic material were introduced to generate voids to reduce the weight of samples as a whole. The substrates were grinding and polished, looking for a SiC surface having low porosity, as porosity is directly related to light scattering that should be avoided on optical surfaces. Laser surface treatments were applied (using or not SiC barbotine) as a method to improve the surface quality. The samples were characterized by optical and laser confocal microscopy, roughness measurements and mechanical tests. The results are very promissory for future applications.

scholarly journals Multifunctional contamination-resistant coatings

2019 ◽  
Vol 215 ◽  
pp. 02002
Author(s):  
Nadja Felde ◽  
Anne Gärtner ◽  
Stefan Schwinde ◽  
Sven Schröder
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Light Scattering ◽  
Structural Design ◽  
Optical Quality ◽  
Optical Systems ◽  
Optical Losses ◽  
High Optical Quality ◽  
Optical Surfaces ◽  
Laser Stability

Surface contaminations can critically affect the performance of optical surfaces, in particular with respect to light scattering, optical losses, and laser stability. Thus, avoiding contaminations and reducing contamination-induced effects is of particular interest in the manufacturing of optical systems. By combining a specific thin film design with a tailored structural design, contamination-resistant coatings with a high optical quality can be realized. Most important is the balance of self-cleaningand light scattering-relevant surface roughness components.

scholarly journals Biomimetic optics: liquid-based optical elements imitating the eye functionality

2020 ◽  
Vol 378 (2167) ◽  
pp. 20190442 ◽  
Author(s):  
Natalia Ivanova
Keyword(s):  
Medical Equipment ◽  
Recent Progress ◽  
Consumer Electronics ◽  
Optical Systems ◽  
Optical Performance ◽  
Theme Issue ◽  
Artificial Eye ◽  
Optical Elements ◽  
Actuation Mechanism ◽  
And Robotics

The optical systems mimicking the eye functions are of great importance in various applications including consumer electronics, medical equipment, machine vision systems and robotics. This optics offers advantages over traditional optical technologies such as the superior adaptation to changing conditions and the comprehensive range of functional characteristics at miniature sizes. This paper presents a review on the recent progress in the development of human eye-inspired optical systems. Liquid-based and elastomer-based tunable optical elements are discussed with the focus on the actuation mechanism, optical performance and the possibility of integration into artificial eye systems. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology (part 3)’.

Development of a metrology technique suitable for in situ measurement and corrective manufacturing of freeform optics

2019 ◽  
Vol 8 (3-4) ◽  
pp. 203-215 ◽  
Author(s):  
Dali Ramu Burada ◽  
Kamal K. Pant ◽  
Vinod Mishra ◽  
Mohamed Bichra ◽  
Gufran Sayeed Khan ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Tool Path ◽  
Optical Systems ◽  
Optical Fabrication ◽  
Optical Surfaces ◽  
Rotationally Symmetric ◽  
Freeform Optics ◽  
Slow Tool Servo ◽  
Metrology System

Abstract The applications of freeform optical surfaces in modern optical systems are providing unique solutions over rotationally symmetric surfaces. These surfaces offer higher degrees of freedom to the designer to enhance the high-end performance of the optical system. The precise metrology of freeform optics is one of the major bottlenecks for its use in imaging applications. Modern optical fabrication methods (i.e. fast or slow tool servo configuration) are, in principle, capable to meet the challenges to generate complex freeform surfaces if supported by precise metrology feedback for error compensation. In the present work, we have developed a Shack-Hartmann sensor-based metrology technique that can be used for quantitative in situ measurement of freeform optics. The sensor head is used to measure freeform optics in the reflection mode by following the CNC tool path in the offline mode. The measurements are used as feedback for corrective machining. Quantitative analysis is also performed to estimate the error budget of the metrology system. Further, the proposed in situ metrology scheme is validated by measuring freeform surface using a coherence correlation interferometric optical profiler.

Design and fabrication of imaging optical systems with freeform surfaces

2012 ◽  
Author(s):  
Xin Zhang ◽  
Ligong Zheng ◽  
Xin He ◽  
Lingjie Wang ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Optical Systems ◽  
Freeform Surfaces

scholarly journals Individual IOL Surface Topography Analysis by the WaveMaster Reflex UV

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Marc Kannengießer ◽  
Achim Langenbucher ◽  
Edgar Janunts
Keyword(s):  
Complex Surface ◽  
Higher Order ◽  
Intraocular Lenses ◽  
Radius Of Curvature ◽  
Freeform Surfaces ◽  
Spherical Surfaces ◽  
Residual Difference ◽  
Quantitative Analysis Method ◽  
Best Fit ◽  
Independent Parameters

Purpose. In order to establish inspection routines for individual intraocular lenses (IOLs), their surfaces have to be measured separately. Currently available measurement devices lack this functionality. The purpose of this study is to evaluate a new topography measurement device based on wavefront analysis for measuring individual regular and freeform IOL surfaces, the “WaveMaster Reflex UV” (Trioptics, Wedel, Germany).Methods. Measurements were performed on IOLs with increasingly complex surface geometries: spherical surfaces, surfaces modelled by higher-order Zernike terms, and freeform surfaces from biometrical patient data. Two independent parameters were measured: the sample’s radius of curvature (ROC) and its residual (difference of sample topography and its best-fit sphere). We used a quantitative analysis method by calculating the residuals’ root-mean-square (RMS) and peak-to-Valley (P2V) values.Results. The sample’s best-fit ROC differences increased with the sample’s complexity. The sample’s differences of RMS values were 80 nm for spherical surfaces, 97 nm for higher-order samples, and 21 nm for freeform surfaces. Graphical representations of both measurement and design topographies were recorded and compared.Conclusion. The measurements of spherical surfaces expectedly resulted in better values than those of freeform surfaces. Overall, the wavefront analysing method proves to be an effective method for evaluating individual IOL surfaces.

Freeform surface descriptions. Part I: Mathematical representations

2017 ◽  
Vol 6 (5) ◽  
Author(s):  
Anika Broemel ◽  
Uwe Lippmann ◽  
Herbert Gross
Keyword(s):  
Optical Systems ◽  
Freeform Surface ◽  
Surface Representation ◽  
Freeform Surfaces ◽  
Mathematical Representations ◽  
The Right

AbstractOptical systems can benefit strongly from freeform surfaces; however, the choice of the right surface representation is not trivial and many aspects must be considered. In this work, we discuss the general approach classical globally defined representations, as well as the basic mathematics and properties of the most commonly used descriptions and present a new description developed by us for describing freeform surfaces.

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