Investigations on Magnetorheological Finishing of High-Quality Optical Surfaces with Varying Influence Function

2010 ◽  
Author(s):  
Markus Schinhaerl ◽  
Christian Vogt ◽  
Florian Schneider ◽  
Peter Sperber ◽  
Rolf Rascher
Keyword(s):  
Influence Function ◽  
Magnetorheological Finishing ◽  
High Quality ◽  
Optical Surfaces

scholarly journals Refractive vs Reflective Correctors

1984 ◽  
Vol 79 ◽  
pp. 549-567
Author(s):  
E.H. Richardson ◽  
C.L. Morbey
Keyword(s):  
Good Combination ◽  
The Other ◽  
Stray Light ◽  
High Quality ◽  
Optical Surfaces ◽  
Other Hand

SummaryImproved designs of refractive correctors produce excellent images with fast telescopes such as those with an F/1.5 prime focus and F/3.5 secondary focus. The fields are flat and there is compensation for the chromatic effect caused by windows. Disadvantages of such correctors are that stray light is produced at the optical surfaces, the elements must be supported at their edges, prerequisite high quality glass is available in only limited sizes, and all wavelengths are not transmitted.Reflective correctors, on the other hand, can produce diffraction limited images at all wavelengths and the mirrors can be supported across their backs as well as at their edges. Disadvantages are that the images are degraded by any substantial window (such as a detector faceplate), there is more central obstruction, and the correctors are sometimes very large and heavy.Except, perhaps, for a specialized telescope, such as one devoted to multi-object slit spectroscopy using fibres, the refractive corrector is preferable at fast foci.A good combination is a Ritchey-Chretien (R-C) telescope with refractive correctors at the fast prime and secondary foci, and a reflective corrector-magnifier for the slow infrared focus.

HyDra: A novel hydrodynamic polishing tool for high quality optical surfaces

2005 ◽  
Author(s):  
Benjamin Martinez ◽  
Manuel Nunez ◽  
Esteban Luna ◽  
Luis Salas ◽  
Irene Cruz-Gonzalez ◽  
...  
Keyword(s):  
High Quality ◽  
Optical Surfaces ◽  
Polishing Tool

scholarly journals Surface Roughness Tuning at Sub-Nanometer Level by Considering the Normal Stress Field in Magnetorheological Finishing

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 997
Author(s):  
Xiaoyuan Li ◽  
Qikai Li ◽  
Zuoyan Ye ◽  
Yunfei Zhang ◽  
Minheng Ye ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Stress Field ◽  
Normal Stress ◽  
Fused Silica ◽  
Fine Tuning ◽  
Magnetorheological Finishing ◽  
Optical Surfaces ◽  
The Impact ◽  
The Relationship

Although magnetorheological finishing (MRF) is being widely utilized to achieve ultra-smooth optical surfaces, the mechanisms for obtaining such extremely low roughness after the MRF process are not fully understood, especially the impact of finishing stresses. Herein we carefully investigated the relationship between the stresses and surface roughness. Normal stress shows stronger impacts on the surface roughness of fused silica (FS) when compared with the shear stress. In addition, normal stress in the polishing zone was found to be sensitive to the immersion depth of the magnetorheological (MR) fluid. Based on the above, a fine tuning of surface roughness (RMS: 0.22 nm) was obtained. This work fills gaps in understanding about the stresses that influence surface roughness during MRF.

Simulation and application of spherical tool influence function for magnetorheological finishing

2021 ◽  
Author(s):  
Hongxiang Wang ◽  
Shiwei Liu ◽  
Qinghua Zhang ◽  
Jing Hou ◽  
Xianhua Chen
Keyword(s):  
Influence Function ◽  
Magnetorheological Finishing ◽  
Tool Influence Function ◽  
Spherical Tool

Relationship between influence function accuracy and polishing quality in magnetorheological finishing

2010 ◽  
Author(s):  
Markus Schinhaerl ◽  
Florian Schneider ◽  
Rolf Rascher ◽  
Christian Vogt ◽  
Peter Sperber
Keyword(s):  
Influence Function ◽  
Magnetorheological Finishing

Optics Manufacturing Using Magnetorheological Finishing

2008 ◽  
Vol 375-376 ◽  
pp. 274-277
Author(s):  
Gui Wen Kang ◽  
Fei Hu Zhang
Keyword(s):  
Dwell Time ◽  
Time Algorithm ◽  
Subsurface Damage ◽  
Numerical Control ◽  
Surface Shape ◽  
Magnetorheological Finishing ◽  
High Quality ◽  
Finishing Process ◽  
Surface Figure

Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. The finishing process can be easily controlled by a computer. Through proper designing of numerical control, sphere and asphere optics can be machined by magnetorheological finishing with high quality. Optical sphere is machined using dwell time algorithm and surface shape 2 pt. PV has been improved from 0.17um to 0.07um.

Discussion on Laser Cleaning of Optical Surface Machined by Magnetorheological Finishing

2010 ◽  
Vol 135 ◽  
pp. 409-412 ◽  
Author(s):  
Gui Wen Kang
Keyword(s):  
Laser Cleaning ◽  
Numerical Control ◽  
Flowing Water ◽  
Optical Surface ◽  
Working Ability ◽  
Magnetorheological Finishing ◽  
High Quality ◽  
Finishing Process ◽  
Optical Manufacturing ◽  
Surface Figure

Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. Through proper designing of numerical control, sphere and asphere optics can be machined by magnetorheological finishing with high quality. Owing to it’s excellence in optical manufacturing, MRF has gained more and more application in industry. Under most conditions the optical surface after MRF would have certain contaminant particles and this would affect its working ability in future use. Formerly the polished workpiece is cleaned by flowing water or ultrasonic cleaning and the contaminat particles couldn’t be totally removed. Laser cleaning is brought forward in this paper and good results could be anticipated.

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