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Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 22, Iss. 6 — Mar. 24, 2014
  • pp: 6464–6477

Speckle reduction and maintaining contrast in a LASER pico-projector using a vibrating symmetric diffuser

Jui-Wen Pan and Chi-Hao Shih  »View Author Affiliations

Optics Express, Vol. 22, Issue 6, pp. 6464-6477 (2014)

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We proposed a design for a LASER pico-projector with a low speckle contrast value and high contrast ratio that maintains system efficiency. The method for speckle contrast reduction utilizes two diffusers and a Voice Coil Motor (VCM) oscillator. The two different diffusers for a high contrast ratio and high system efficiency can be divided into two categories. In Category 1, the speckle contrast value can be decreased to 2.80% by using a circular symmetric diffuser. At the same time, the full-on/full-off (FO:FO) contrast ratio can be maintained within 1200:1-1300:1, but the system efficiency decreases 1.50%. In Category 2, the speckle contrast value can be reduced to 6.50% by using an elliptically scattering diffuser. At the same time, the FO:FO contrast ratio can be maintained within 1300:1-1400:1, and the system efficiency decreases by only 1.00%.

© 2014 Optical Society of America

OCIS Codes
(030.6140) Coherence and statistical optics : Speckle
(140.2020) Lasers and laser optics : Diode lasers
(220.4830) Optical design and fabrication : Systems design
(220.2945) Optical design and fabrication : Illumination design

ToC Category:
Coherence and Statistical Optics

Original Manuscript: December 23, 2013
Revised Manuscript: February 21, 2014
Manuscript Accepted: February 25, 2014
Published: March 12, 2014

Jui-Wen Pan and Chi-Hao Shih, "Speckle reduction and maintaining contrast in a LASER pico-projector using a vibrating symmetric diffuser," Opt. Express 22, 6464-6477 (2014)

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