scholarly journals A new approach to laser polishing and form correction of optical components

2019 ◽  
Vol 215 ◽  
pp. 09001
Author(s):  
Harold Kessler ◽  
Roelene Botha ◽  
Carsten Ziolek

The increasing variety of optical components and materials, combined with stricter surface tolerance requirements, necessitate refining existing polishing processes and developing innovative new polishing solutions and metrology technologies. A fast, reproducible laser polishing process would offer considerable economic benefits over conventional mechanical polishing processes and interest a broad variety of optics manufacturers. In this work, a holistic approach is taken to address the various aspects of glass polishing and form correction via a novel laser polishing system design, the use of a measurement strategy that can be integrated inline and simulation results that are correlated with process parameter studies for different materials.

2010 ◽  
Vol 26-28 ◽  
pp. 1147-1150
Author(s):  
Zong Li Liu ◽  
Jie Cao ◽  
Zhan Ting Yuan

This paper proposes a new approach to determining the complex system design for a product mix comprising complex hierarchies of subassembly and components. Pareto Ant Colony Optimisation as an especially effective meta-heuristic for solving the problem of complex system design was introduced in this paper. A Pareto Optimal Set of complex system in which only the non dominated solutions allow ants to deposit pheromones over the time and cost pheromone matrices after certain generation runs. Simulation results show that the model for complex system and the hybrid algorithms are effective to the design of complex system.


2010 ◽  
Vol 438 ◽  
pp. 65-72 ◽  
Author(s):  
Andreas Mehner ◽  
Ju An Dong ◽  
Timo Hoja ◽  
Torsten Prenzel ◽  
Yildirim Mutlugünes ◽  
...  

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.


2014 ◽  
Vol 575 ◽  
pp. 766-770 ◽  
Author(s):  
Benoit Rosa ◽  
Jean Yves Hascoet ◽  
Pascal Mognol

Laser polishing is a finishing process based on melting material, with the objective of improving surface topography. Some operating parameters must be taken into consideration, such as laser power, feed rate, offset, and overlapping. Moreover, because of its dependence on the primary process, the initial topography has also an impact on the final result. This study describes a quadratic model, conceived to optimize final topography according to the primary process and laser polishing. Based on an experimental matrix, the model takes into account both laser operating parameters and the initial topography, in order to predict polished surfaces and to determine optimal set of parameters. After the phase of experimentation and the creation of the quadratic model, an optimal final topography is introduced, taking into account the initial surface and the laser parameters.


2003 ◽  
Vol 13 (06) ◽  
pp. 1599-1608 ◽  
Author(s):  
Chao Tao ◽  
Gonghuan Du ◽  
Yu Zhang

In this paper, we propose a new approach to breaking down chaotic communication scheme by attacking its encryption keys. A remarkable advancement is that it can decode the hidden message exactly. This makes it become possible to break down some cascaded chaotic communication systems. We also decode digital information from the cascaded heterogeneous chaotic communication system and give the simulation results.


2014 ◽  
Vol 536-537 ◽  
pp. 1527-1531
Author(s):  
Ya Feng Li ◽  
Zi Wei Zheng

The Series Dynamic Voltage Regulator can compensate the harmonics distortion caused by voltage type harmonic source This paper presents a new approach of detecting harmonic voltage in dq0 coordinates, based on the generalized instantaneous reactive power ,and used in the series dynamic voltage regulator successfully. It is demonstrated by theoretical analysis and simulation results that the proposed detecting method of harmonic voltage is correct and valid.


2012 ◽  
Vol 523-524 ◽  
pp. 1001-1005 ◽  
Author(s):  
Martin Hünten ◽  
Daniel Hollstegge ◽  
Fritz Klocke

Manufacturing of micro optical components is approached with many different technologies. In this paper it is presented how the precision glass molding process is enabled to manufacture micro optical components made out of glass. In comparison to the existing glass molding technology the new approach aims for molding entire glass wafers including multiple micro optical components. It is explained which developments in the filed of simulation, mold manufacturing and molding were accomplished in order to enable the precision glass molding on wafer scale.


Author(s):  
Sérgio Correia ◽  
Marko Beko ◽  
Luís Cruz ◽  
Slavisa Tomic

This work addresses the energy-based source localization problem in wireless sensors networks. Instead of circumventing the maximum likelihood (ML) problem by applying convex relaxations and approximations (like all existing approaches do), we here tackle it directly by the use of metaheuristics. To the best of our knowledge, this is the first time that metaheuristics is applied to this type of problems. More specifically an elephant herding optimization (EHO) algorithm is applied. Through extensive simulations, the key parameters of the EHO algorithm are optimized such that they match the energy decay model between two sensor nodes. A detailed analysis of the computational complexity is presented, as well as performance comparison between the proposed algorithm and existing non-metaheuristic ones. Simulation results show that the new approach significantly outperforms the existing solutions in noisy environments, encouraging further improvement and testing of metaheuristic methods.


2021 ◽  
Vol 71 (1) ◽  
pp. 124-133
Author(s):  
B. K. Tiwari ◽  
R. Sharma

This paper presents the design and analysis of the ‘Variable Buoyancy System (VBS)’ for depth control which is an essential operation for all underwater vehicles. We use the ‘Water Hydraulic Variable Buoyancy System (WHVBS)’ method to control the buoyancy and discuss details of the system design architecture of various components of VBS. The buoyancy capacity of the developed VBS is five kilograms and the performance of the VBS in standalone mode is analysed using numerical simulation. Presented VBS is operable to control the buoyancy up to sixty meters of depth and it can be directly installed to medium size UVs. Simulation results show that the developed VBS can reduce the energy consumption significantly and higher in each cycle (i.e. descending and ascending) of the same VBS in standalone mode being operated with either propeller or thruster for sixty meters depth of operation. Our results conclude and demonstrate that the designed VBS is effective in changing the buoyancy and controlling the heave velocity efficiently and this serves the purpose of higher endurance and better performances desired in rescue/attack operations related to the UVs both in civilian and defense domains.


2000 ◽  
Author(s):  
M. Modigell ◽  
M. Weng

Abstract The present paper proposes a new approach to analyse the conversion of complexly composed particles that are dispersed in a cyclone gas flow at high temperatures. The numeric simulation of flow field and particle trajectories is coupled with a thermodynamic equilibrium calculation which describes the particle reaction progress. First simulation results and the comparison with experimental data are shown in this paper.


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