Paper
6 February 2012 Performance of correlated speckle patterns for speckle reduction in laser projectors
Sigbjørn Vindenes Egge, Ulf Österberg, Astrid Aksnes
Author Affiliations +
Proceedings Volume 8280, Advances in Display Technologies II; 82800D (2012) https://doi.org/10.1117/12.905898
Event: SPIE OPTO, 2012, San Francisco, California, United States
Abstract
If the arc lamp in standard display projectors is replaced by lasers, the projector can gain several advantages such as improved color gamut, higher contrast and brightness. Coherent by nature, the laser also adds one significant disadvantage to the projector: the presence of speckle, which manifests itself as noise-like intensity fluctuations over the image. In this paper, we present an overview of our work concerning correlated speckle patterns. We give general formulas for the speckle contrast of the sum of N partially correlated speckle patterns. It is shown how the speckle contrast depends on the correlations between the individual speckle patterns, and for the case of a fully developed speckle pattern we present a general expression for the correlations. As an example, we look at speckle suppression by discrete rotation of a diffraction pattern on a diffuser. We use a sinusoidal phase grating which has the advantage that the zeroth order can be extinguished without loss of power. Hence, no part of the diffraction pattern remains stationary when rotated. Expressions for correlations are found, with different degrees of generality, which enable us to find expressions for the contrast. Furthermore, the influence of the diffraction pattern's complex amplitude distribution on the correlation and speckle contrast is investigated.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Sigbjørn Vindenes Egge, Ulf Österberg, and Astrid Aksnes "Performance of correlated speckle patterns for speckle reduction in laser projectors", Proc. SPIE 8280, Advances in Display Technologies II, 82800D (6 February 2012); https://doi.org/10.1117/12.905898
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Speckle pattern

Speckle

Projection systems

Diffraction

Diffusers

Current controlled current source

Diffraction gratings

Back to Top