OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 15 — Jul. 16, 2012
  • pp: 16552–16566

Low speckle laser illuminated projection system with a vibrating diffractive beam shaper

Po-Hung Yao, Chieh-Hui Chen, and Cheng-Huan Chen  »View Author Affiliations

Optics Express, Vol. 20, Issue 15, pp. 16552-16566 (2012)

View Full Text Article

Enhanced HTML    Acrobat PDF (4170 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



Currently the major issues in applying the laser as an illumination source for projectors are beam shaping and laser speckle. We present a compact total solution for both issues by using a diffractive beam shaper associated with a cylindrical lens for the illumination optics and a vibrating motor attached to the beam shaper to eliminate speckle on the projection screen. The diffractive beam shaper features a double-sided microlens array with a lateral shift to each other. The illumination pattern is free of zero diffraction order mainly due to the continuous and spherical surface relief of the lenslet, which can be accurately fabricated with diamond turning and injection molding without quantizing surface relief, so that the illumination pattern on the microdisplay can match the design very well with high diffraction efficiency. In addition, the vibration of the diffractive beam shaper in the longitudinal mode has been found effective for eliminating the dot pattern in the illumination and reducing laser speckle on the projection screen. The proposed laser illuminator has been implemented on a three-panel LCoS projector engine to replace the traditional UHP lamp. The uniformity and speckle contrast are measured to be 78% and 5.5% respectively, which demonstrates the feasibility and potential of the proposed scheme.

© 2012 OSA

OCIS Codes
(110.6150) Imaging systems : Speckle imaging
(120.2040) Instrumentation, measurement, and metrology : Displays
(220.4000) Optical design and fabrication : Microstructure fabrication
(110.2945) Imaging systems : Illumination design

ToC Category:
Imaging Systems

Original Manuscript: May 23, 2012
Revised Manuscript: June 25, 2012
Manuscript Accepted: June 25, 2012
Published: July 6, 2012

Po-Hung Yao, Chieh-Hui Chen, and Cheng-Huan Chen, "Low speckle laser illuminated projection system with a vibrating diffractive beam shaper," Opt. Express 20, 16552-16566 (2012)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. C. M. Chang and H. P. D. Shieh, “Design of illumination and projection optics for projectors with single digital micromirror devices,” Appl. Opt.39(19), 3202–3208 (2000). [CrossRef] [PubMed]
  2. X. Zhao, Z. L. Fang, J. C. Cui, X. Zhang, and G. G. Mu, “Illumination system using LED sources for pocket-size projectors,” Appl. Opt.46(4), 522–526 (2007). [CrossRef] [PubMed]
  3. J. W. Pan, C. M. Wang, H. C. Lan, W. S. Sun, and J. Y. Chang, “Homogenized LED-illumination using microlens arrays for a pocket-sized projector,” Opt. Express15(17), 10483–10491 (2007). [CrossRef] [PubMed]
  4. P. C. Chen, C. C. Chen, P. H. Yao, and C. H. Chen, “Double side lenslet array for illumination optics of laser projector,” Proc. SPIE7232, 72320X, 72320X-9 (2009). [CrossRef]
  5. S. Zhang, “A simple bi-convex refractive laser beam shaper,” J. Opt. A, Pure Appl. Opt.9(10), 945–950 (2007). [CrossRef]
  6. F. Wippermann, U.-D. Zeitner, P. Dannberg, A. Bräuer, and S. Sinzinger, “Beam homogenizers based on chirped microlens arrays,” Opt. Express15(10), 6218–6231 (2007). [CrossRef] [PubMed]
  7. C. Dorrer and J. D. Zuegel, “Design and analysis of binary beam shapers using error diffusion,” J. Opt. Soc. Am. B24(6), 1268–1275 (2007). [CrossRef]
  8. R. M. Tasso, Sales, Geoffrey Gretton, G. Michael Morris, and Daniel H. Raguin, “Beam shaping and homogenization with random microlens arrays,” in Diffractive Optics and Micro-Optics, R. Magnusson, ed., Vol. 75 of OSA Trends in Optics and Photonics Series (Optical Society of America, 2002), paper DMA3.
  9. J. W. Goodman, Speckle Phenomena in Optics: Theory and Applications (Roberts & Company, 2006).
  10. J. W. Goodman, “Some fundamental properties of speckle,” J. Opt. Soc. Am.66(11), 1145–1150 (1976). [CrossRef]
  11. A. Furukawa, N. Ohse, Y. Sato, D. Imanishi, K. Wakabayashi, S. Ito, K. Tamamura, and S. Hirata, “Effective speckle reduction in laser projection displays,” Proc. SPIE6911, 69110T, 69110T-7 (2008). [CrossRef]
  12. G. M. J. Craggs, F. Riechert, Y. Meuret, H. Thienpont, U. Lemmer, and G. Verschaffelt, “Low-speckle laser projection using farfield nonmodal emission of a broad-area vertical-cavity surface-emitting laser,” Proc. SPIE7720, 772020, 772020-8 (2010). [CrossRef]
  13. M. N. Akram, V. Kartashov, and Z. M. Tong, “Speckle reduction in line-scan laser projectors using binary phase codes,” Opt. Lett.35(3), 444–446 (2010). [CrossRef] [PubMed]
  14. T. Iwai and T. Asakura, “Speckle reduction in coherent information processing,” Proc. IEEE84(5), 765–781 (1996). [CrossRef]
  15. L. L. Wang, T. Tschudi, T. Halldórsson, and P. R. Pétursson, “Speckle reduction in laser projection systems by diffractive optical elements,” Appl. Opt.37(10), 1770–1775 (1998). [CrossRef] [PubMed]
  16. L. L. Wang, T. Tschudi, M. Boeddinghaus, A. Elbert, T. Halldorsson, and P. Petursson, “Speckle reduction in laser projections with ultrasonic waves,” Opt. Eng.39(6), 1659–1664 (2000). [CrossRef]
  17. M. N. Akram, Z. M. Tong, G. M. Ouyang, X. Y. Chen, and V. Kartashov, “Laser speckle reduction due to spatial and angular diversity introduced by fast scanning micromirror,” Appl. Opt.49(17), 3297–3304 (2010). [CrossRef] [PubMed]
  18. E. G. Rawson, A. B. Nafarrate, R. E. Norton, and J. W. Goodman, “Speckle-free rear-projection screen using two close screens in slow relative motion,” J. Opt. Soc. Am.66(11), 1290–1294 (1976). [CrossRef]
  19. G. Ouyang, Z. M. Tong, M. N. Akram, K. V. Wang, V. Kartashov, X. Yan, and X. Y. Chen, “Speckle reduction using a motionless diffractive optical element,” Opt. Lett.35(17), 2852–2854 (2010). [CrossRef] [PubMed]
  20. L. Golan and S. Shoham, “Speckle elimination using shift-averaging in high-rate holographic projection,” Opt. Express17(3), 1330–1339 (2009). [CrossRef] [PubMed]

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.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited