OSA's Digital Library

Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Editor: James C. Wyant
  • Vol. 46, Iss. 36 — Dec. 20, 2007
  • pp: 8668–8673

Microforging technique for rapid, low-cost fabrication of lens array molds

Craig R. Forest, Miguel A. Saez, and Ian W. Hunter  »View Author Affiliations


Applied Optics, Vol. 46, Issue 36, pp. 8668-8673 (2007)
http://dx.doi.org/10.1364/AO.46.008668


View Full Text Article

Enhanced HTML    Acrobat PDF (1041 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

Interest in micro-optical components for applications ranging from telecommunications to life sciences has driven the need for accessible, low-cost fabrication techniques. Many microlens fabrication processes are unsuitable for applications requiring 100% fill factor, apertures 1000 μm with high numerical aperture, and scalability to large areas (e.g., tens of centimeters to meters) with millions of lenses. We report on a flexible, low-cost mold fabrication technique that utilizes a combination of milling and microforging. The technique involves first performing a rough cut with a ball-end mill. Final shape and sag height are then achieved by pressing a sphere of equal diameter into the milled divot. Using this process, we have fabricated molds for rectangular arrays of 1–10,000 lenses with apertures of 25 1600 μm , sag heights of 3 130 μm , interlens spacings of 250 2000 μm , and fill factors up to 100%. Mold profiles have a roughness and figure error of 68 nm and 354 nm , respectively, for 100% fill factor, 1000 μm aperture lenses. The required forging force was modeled as a modified open-die forging process and experimentally verified to increase nearly linearly with surface area. The optical performance of lens arrays injection molded from microforged molds was characterized by imaging the point spread function and was found to be in the range of theoretical values. The process can be easily adapted to lenticular arrays as well. Limitations include milling machine range and accuracy.

© 2007 Optical Society of America

OCIS Codes
(120.4610) Instrumentation, measurement, and metrology : Optical fabrication
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
(120.6660) Instrumentation, measurement, and metrology : Surface measurements, roughness
(220.4000) Optical design and fabrication : Microstructure fabrication

ToC Category:
Instrumentation, Measurement, and Metrology

History
Original Manuscript: September 4, 2007
Revised Manuscript: October 11, 2007
Manuscript Accepted: October 16, 2007
Published: December 19, 2007

Citation
Craig R. Forest, Miguel A. Saez, and Ian W. Hunter, "Microforging technique for rapid, low-cost fabrication of lens array molds," Appl. Opt. 46, 8668-8673 (2007)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-46-36-8668


Sort:  Year  |  Journal  |  Reset  

References

  1. S. Morgenthaler and W. G. Thilly, "Summed multi-allelic risk: logical and statistical models for discovery of carrier genes in human populations," Mutat. Res. 615, 28-56 (2007). [CrossRef]
  2. M. Fritze, M. B. Stern, and P. W. Wyatt, "Laser-fabricated glass microlens arrays," Opt. Lett. 23, 141-143 (1998). [CrossRef]
  3. T. R. Jay and M. B. Stern, "Preshaping photoresist for refractive microlens fabrication," Opt. Eng. 33, 3552-3555 (1994). [CrossRef]
  4. H. Yang, C.-K. Chao, M.-K. Wei, and C.-P. Lin, "High fill-factor microlens array mold insert fabrication using a thermal reflow process," J. Micromec. Microeng. 14, 1197-1204 (2004). [CrossRef]
  5. N. F. Borelli and D. K. Morse, "Microlens array produced by a photolytic technique," Appl. Opt. 27, 476-479 (1988). [CrossRef]
  6. M. Oikawa, K. Iga, S. Misawa, and Y. Kokubun, "Improved distributed-index planar microlens and its application to 2-D lightwave components," Appl. Opt. 22, 441-442 (1983). [CrossRef] [PubMed]
  7. D. L. MacFarlane, V. Narayan, J. A. Tatum, W. R. Cox, T. Chen, and D. J. Hayes, "Microjet fabrication of microlens arrays," IEEE Photon. Technol. Lett. 9, 1112-1114 (1994). [CrossRef]
  8. Y.-C. Lee, C.-M. Chen, and C.-Y. Wu, "Spherical and aspheric microlenses fabricated by excimer laser LIGA-like process," J. Manuf. Sci. Eng. 129, 126-134 (2007). [CrossRef]
  9. S. Kalpakjian and S. Schmid, Manufacturing Engineering and Technology (Academic, 2001).
  10. E. Hecht, Optics (Academic, 2001).

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Figures

Fig. 1 Fig. 2 Fig. 3
 
Fig. 4 Fig. 5
 

« Previous Article

OSA is a member of CrossRef.

CrossCheck Deposited