Abstract

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

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  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]

2010

2009

L. Golan and S. Shoham, “Speckle elimination using shift-averaging in high-rate holographic projection,” Opt. Express17(3), 1330–1339 (2009).
[CrossRef] [PubMed]

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]

2008

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]

2007

2000

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]

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]

1998

1996

T. Iwai and T. Asakura, “Speckle reduction in coherent information processing,” Proc. IEEE84(5), 765–781 (1996).
[CrossRef]

1976

Akram, M. N.

Asakura, T.

T. Iwai and T. Asakura, “Speckle reduction in coherent information processing,” Proc. IEEE84(5), 765–781 (1996).
[CrossRef]

Boeddinghaus, M.

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]

Bräuer, A.

Chang, C. M.

Chang, J. Y.

Chen, C. C.

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]

Chen, C. H.

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]

Chen, P. C.

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]

Chen, X. Y.

Craggs, G. M. J.

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]

Cui, J. C.

Dannberg, P.

Dorrer, C.

Elbert, A.

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]

Fang, Z. L.

Furukawa, A.

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]

Golan, L.

Goodman, J. W.

Halldorsson, T.

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]

Halldórsson, T.

Hirata, S.

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]

Imanishi, D.

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]

Ito, S.

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]

Iwai, T.

T. Iwai and T. Asakura, “Speckle reduction in coherent information processing,” Proc. IEEE84(5), 765–781 (1996).
[CrossRef]

Kartashov, V.

Lan, H. C.

Lemmer, U.

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]

Meuret, Y.

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]

Mu, G. G.

Nafarrate, A. B.

Norton, R. E.

Ohse, N.

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]

Ouyang, G.

Ouyang, G. M.

Pan, J. W.

Petursson, P.

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]

Pétursson, P. R.

Rawson, E. G.

Riechert, F.

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]

Sato, Y.

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]

Shieh, H. P. D.

Shoham, S.

Sinzinger, S.

Sun, W. S.

Tamamura, K.

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]

Thienpont, H.

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]

Tong, Z. M.

Tschudi, T.

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]

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]

Verschaffelt, G.

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]

Wakabayashi, K.

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]

Wang, C. M.

Wang, K. V.

Wang, L. L.

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]

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]

Wippermann, F.

Yan, X.

Yao, P. H.

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]

Zeitner, U.-D.

Zhang, S.

S. Zhang, “A simple bi-convex refractive laser beam shaper,” J. Opt. A, Pure Appl. Opt.9(10), 945–950 (2007).
[CrossRef]

Zhang, X.

Zhao, X.

Zuegel, J. D.

Appl. Opt.

J. Opt. A, Pure Appl. Opt.

S. Zhang, “A simple bi-convex refractive laser beam shaper,” J. Opt. A, Pure Appl. Opt.9(10), 945–950 (2007).
[CrossRef]

J. Opt. Soc. Am.

J. Opt. Soc. Am. B

Opt. Eng.

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]

Opt. Express

Opt. Lett.

Proc. IEEE

T. Iwai and T. Asakura, “Speckle reduction in coherent information processing,” Proc. IEEE84(5), 765–781 (1996).
[CrossRef]

Proc. SPIE

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]

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]

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]

Other

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.

J. W. Goodman, Speckle Phenomena in Optics: Theory and Applications (Roberts & Company, 2006).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (21)

Fig. 1
Fig. 1

Schematic architecture of laser projection system with vibrating diffractive beam shaper.

Fig. 2
Fig. 2

Top-view image of the double-sided microlens array with lateral shift to each other. (Solid line: lenslet on the top side of substrate; dash line: lenslet on the down side of substrate)

Fig. 3
Fig. 3

Schematic diagram of laser beam propagating through the double-sided microlens array.

Fig. 4
Fig. 4

Simulated intensity distribution of the optimized diffractive beam shaper at (a) z0 = 164 mm and (b) z0 = 5 m.

Fig. 5
Fig. 5

Fabrication process of the double-sided microlens array beam shaper.

Fig. 6
Fig. 6

Master molds of the double-sided microlens array.

Fig. 7
Fig. 7

Measured images of the master mold taken from a confocal laser microscope. (a) Cross section along x-axis (b) Cross section along y-axis.

Fig. 8
Fig. 8

Double-sided microlens array beam shaper.

Fig. 9
Fig. 9

Cross sectional distribution of illumination patterns of (a) red, (b) green and (c) blue lasers.

Fig. 10
Fig. 10

DC-current response of the vibration motor.

Fig. 11
Fig. 11

Intensity distribution on the microdisplay in the transverse mode. (a) Intensity distribution at various vibrating position. (b) Superimposed intensity distribution from simulation and measurement.

Fig. 12
Fig. 12

Intensity distribution at the central area of microdisplay with transverse shifts of the beam shaper at 0, 160 and 300μm.

Fig. 13
Fig. 13

Intensity distribution on the microdisplay in the longitudinal mode. (a) Intensity distribution at various vibrating position. (b) Superimposed intensity distribution from simulation and measurement.

Fig. 14
Fig. 14

Intensity distribution at the central area of microdisplay with longitudinal shifts of the beam shaper at 0, 160 and 300μm.

Fig. 15
Fig. 15

Experiment setup for evaluating speckle pattern on the projection screen.

Fig. 16
Fig. 16

Speckle contrast versus driving current to the motor operated in the longitudinal vibration mode.

Fig. 17
Fig. 17

Speckle contrast versus driving current to the motor operated in the transverse vibration mode.

Fig. 18
Fig. 18

Cross-sectional intensity distribution without vibration (dash line) and with vibration at 60mA (solid line) on the projection screen in the longitudinal vibration mode.

Fig. 19
Fig. 19

Cross sectional intensity distribution of projection pattern at central region of the screen with longitudinal displacement of the beam shaper at 0, 160 and 300μm.

Fig. 20
Fig. 20

(a) Cylindrical lens put against diffractive beam shaper for modifying aspect ratio of illumination pattern. (b) Schematic architecture of three-panel LCoS projection system with light path.

Fig. 21
Fig. 21

Snapshot of the animation film projected from 3-panel LCoS laser projection system. (a) without vibration (b) with vibration of the beam shaper. (Original picture from the film UP. Courtesy of Walt Disney Studios Motion Pictures Taiwan)

Tables (4)

Tables Icon

Table 1 Measured Structure Parameters of Lenslet on the Master Mold

Tables Icon

Table 2 Illumination Pattern at Different z0 of the Diffractive Beam Shaper with Red, Green and Blue Lasers

Tables Icon

Table 3 Optical Performance of the Diffractive Beam Shaper

Tables Icon

Table 4 RGB Projection Images without and with Vibration (at current of 60mA) of the Beam Shaper

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

U o (x,y;z)= Σ U m (ζ,η)h(xζ,yη)dζdη
T(ζ,η)=ψ(ζ,η)/k(n1)
T(ζ,η)= [ R 2 (ζp(m+ 1 2 )) 2 (ηp(q+ 1 2 )) 2 ] 1 2 + T s + [ R 2 (ζp(m+ 1 2 )Δζ) 2 (ηp(q+ 1 2 )Δη) 2 ] 1 2
C= σ s I ¯

Metrics