Abstract
A new surface figuring machine called Helios 1200 is presented in this paper. It is designed for the figuring of meter sized optical surfaces with form accuracy correction capability better than 20 nm rms within a reduced number of iterations. Unlike other large figuring facilities using energy beams, Helios 1200 operates a plasma torch at atmospheric pressure, offers a high material removal rate, and a relatively low running cost. This facility is ideal to process large optical components, lightweight optics, silicon based and difficult to machine materials, aspheric, and free form surfaces. Also, the surfaces processed by the reactive atom plasma (RAP) are easy to fine polish through hand conventional sub-aperture polishing techniques. These unique combined features lead to a new capability for the fabrication of optical components opening up novel design possibilities for optical engineers. The key technical features of this large RAP machine are fast figuring capabilities, non-contact material removal tool, the use of a near Gaussian footprint energy beam, and a proven tool path strategy for the management of the heat transfer. Helios 1200 complies with the European machine safety standard and can be used with different types of reactive gases using either fluorine or chlorine compounds. In this paper, first the need for large optical component is discussed. Then, the RAP facility is described: radio frequency R.F generator, plasma torch, and 3 axis computer numerically controlled motion system. Both the machine design and the performance of the RAP tool is assessed under specific production conditions and in the context of meter class mirror and lens fabrication.
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Abbreviations
- CELT:
-
California extremely large telescope
- CCP:
-
Capacitively coupled plasma
- CF4 :
-
Carbon tetra-fluoride
- CPP:
-
Continuous phase plate
- EUVL:
-
Extreme ultra violet lithography
- ELT:
-
Extremely large telescopes
- FWHM:
-
Full width at half maximum
- IBF:
-
Ion beam figuring
- ICP:
-
Inductively coupled plasma
- NF3 :
-
Nitrogen tri-fluoride
- RF:
-
Radio frequency
- ROC:
-
Radius of curvature
- RAP:
-
Reactive atom plasma
- RMS:
-
Root mean square
- SWR:
-
Standing wave ration
- SF6 :
-
Sulfur hexafluoride
References
Allen LN, Keim RE, Lewis TS, Ullom JR (1992) Surface error correction of a Keck 10-m telescope primary mirror segment by ion figuring. In: Proceedings of SPIE, advanced optical manufacturing and testing II1531. doi:10.1117/12.134862
Shore P, May-Miller R (2003) Production challenge of the optical segments for extra large telescopes. In: Proceedings of international progress on advanced optics and sensors, pp 25–30
Jiang JX, Shore P, McKeown P, Whitehouse D (2012) Ultra-precision engineering: from physics to manufacturing. Philos Trans R Soc A. doi:10.1098/rsta.2012.0178
Frost F, Fechner R, Ziberi B, Völlner J, Flamm D, Schindler A (2009) Large area smoothing of surfaces by ion bombardment: fundamentals and applications. J Phys: Condens Matter 21:224026. doi:10.1088/0953-8984/21/22/224026
Arnold T, Boehm G, Fechner R, Meister J, Nickel A, Frost F, Haensel T, Schindler A (2010) Ultra-precision surface finishing by ion beam and plasma jet techniques status and outlook. Nucl Instrum Methods Phys Res A 616:147–156. doi:10.1016/j.nima.2009.11.013
Ando M, Numata A, Saito N, Taniguchi J, MiyamotoI (2004) Development of ion beam figuring system for mirror shape correction of minute area, oral presentation slides. In: Conference of EUVA
Jacobs S, Shorey AB (2000) Magnetorheological finishing: new fluids for new materials. In: Conference paper of optical fabrication and testing (OF&T), OSA technical digest, paper OWB1 pp 142–144
Harris D (2011) History of magnetorheological finishing. In: Proceedings of SPIE, Window and Dome Technologies and Materials XII, vol 8016. doi:10.1117/12.882557
Yamamura K, Sano Y, Shibahara M, Yamauchi K, Mimura H, Endo K, Mori Y (2006) Ultra-precision machining utilizing numerically controlled scanning of localized atmospheric pressure plasma. Jpn J Appl Phys 45:8270–8276. doi:10.1143/JJAP.45.8270
Yamamura K, Mimura H, Yamauchi K, Sano Y, Saito A, Kinoshita T, Endo K, Mori Y, Souvorov A, Yabashi M, Tamasaku K, Ishikawa T (2002) Aspheric surface fabrication in nm-level accuracy by numerically controlled plasma chemical vaporization machining (CVM) and elastic emission machining (EEM). In: Proceedings of SPIE, X-ray mirrors, crystals, and multilayers II, 4782: 265–270. doi:10.1117/12.453749
Takino H, Yamamura K, Sano Y, Mori Y (2010) Removal characteristics of plasma chemical vaporization machining with a pipe electrode for optical fabrication. Appl Opt 49:4434–4440. doi:10.1364/AO.49.004434
Zhang J, Wang B, Dong S (2008) Application of atmospheric pressure plasma polishing method in machining of silicon ultra-smooth surfaces. Front Electr Electron Eng China 3(4):480–487. doi:10.1007/s11460-008-0072-9
Bo W, Jufan Z, Shen D (2009) New development of atmospheric pressure plasma polishing. Chin Opt Lett 7(6):537–538. doi:10.3788/COL20090706.0537
Arnold T, Boehm G (2012) Application of atmospheric plasma jet machining (PJM) for effective surface figuring of SiC. Precis Eng 36:546–553. doi:10.1016/j.precisioneng.2012.04.001
Arnold T, Boehm G, Paetzelt H (2012) Plasma jet machining based process chain for the manufacturing of complex shaped synchrotron mirrors. In: 12th conference of Euspen, pp Nr. P6.05
Revella PJ, Goldspinka GF (1984) A review of reactive ion beam etching for production. In: Vacuum special issue: proceedings of the SIRA international seminar, film preparation and etching using vacuum or plasma technology, vol 34, no 3–4, pp 455–462
Castelli M, Jourdain R, Morantz P, Shore P (2011) Reactive atom plasma for rapid figure correction of optical surfaces. Key Eng Mater Precis Mach VI 496:182–187
Jourdain R, Castelli M, Shore P, Subrahmanyan P (2010) Process characterisation and key tasks for cost-effective 3D figuring of specular surfaces using RAP. In: 10th Conference of Euspen, pp 185–188
Verma Y, Chang AK, Berrett JW, Futtere K, Gardopee GJ, Kelley J, Kyler T, Lee J, Lyford N, Proscia D, Sommer PR (2006) Rapid damage-free shaping of silicon carbide using reactive atom plasma (RAP) processing. In: Proceedings of SPIE, optical fabrication for large telescopes II, vol 6273. doi:10.1117/12.671969
Webb K (2007) Advances in fabrication technologies for light weight CVC SiC mirrors. In: Proceedings of SPIE 6666: 01–06
Fanara C, Shore P, Nicholls JR, Lyford N, Kelley J, Carr J, Sommer P (2006) A new reactive atom plasma technology (RAPT) for precision machining: the etching of ULE surfaces. Adv Eng Mater 8:933–939. doi:10.1002/adem.200600028
Paul KC, Hatazawa S, Takahashi M, Cliteur GJ, Sakuta T (1999) Diagnoses of inductively coupled SF6 and N2 plasmas at atmospheric pressure. Thin Solid Films 345(1):134–139. doi:10.1016/S0040-6090(99)00103-0
D’Agostino R, Flamm DL (1981) Plasma etching of Si and SiO2 in SF6-O2 mixtures. J Appl Phys 52:162–167. doi:10.1063/1.328468
Tamkin JM, Milster TD (2010) Effects of structured mid-spatial frequency surface errors on image performance. Appl Opt 49:6522–6535. doi:10.1364/AO.49.006522
Mast T, Nelson J, Sommargren G (2000) Primary mirror segment fabrication for CELT. In: Proceedings of SPIE: optical design, materials, fabrication, and maintenance, vol 4003. doi:10.1117/12.391538
Néauport J, Ribeyre X, Daurios J, Valla D, Lavergne M, Beau V, Videau L (2003) Design and optical characterization of a large continuous phase plate for laser integration line and laser Megajoule facilities. Appl Opt 42:2377–2382. doi:10.1364/AO.42.002377
Castelli M, Jourdain R, Morantz P, Shore P (2012) Rapid optical surface figuring using reactive atom plasma. J Precis Eng 36:467–476. doi:10.1016/j.precisioneng.2012.02.005
Jourdain R, Castelli M, Morantz P, Shore P (2012) Plasma surface figuring of large optical components. In: Proceedings of SPIE, optical micro- and nanometrology IV, vol 8430 doi:10.1117/12.924798
Inventor: Kelley J, Carr JW, Fiske PS, Chang A (2005) Assignee: RAPT Industries Inc., Patent PCT/US 2005/00061774 A1
Eckert HU (1974) The induction arc: a state of the art review. High Temp Sci 6:99–134
Boulos I (1985) The inductively coupled RF (radio frequency) plasma. Pure Appl Chem 57:1321–1352
Jourdain R, Morantz P, Shore P (2013) Optical test system for meter scale optics. Optics express (to be submitted)
Acknowledgments
This research work was funded by the Cranfield Innovative Manufacturing Research Centre (2007–2012) of the Engineering and Physical Sciences Research Council UK.
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Jourdain, R., Castelli, M., Shore, P. et al. Reactive atom plasma (RAP) figuring machine for meter class optical surfaces. Prod. Eng. Res. Devel. 7, 665–673 (2013). https://doi.org/10.1007/s11740-013-0467-1
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DOI: https://doi.org/10.1007/s11740-013-0467-1