Abstract

We use projection screens filled with colloidal dispersions to reduce laser speckle in laser projection systems. Laser light is multiply scattered at the globules of the colloidal dispersion’s internal phase, which do Brownian movement. The integration time of the human eye causes a perception of a reduced laser speckle contrast because of temporal averaging. As a counteracting effect, blurring of projected images occurs in the colloidal dispersion, which degrades image quality. We measure and compare speckle reduction and blurring of three different colloidal dispersions filled into transmission screens of different thicknesses. We realized a high speckle contrast reduction at simultaneously low blurring with a thin screen filled with a highly scattering colloidal dispersion with forward-peaked scattering. We realize speckle contrast values below 3% at acceptable blurring.

© 2009 Optical Society of America

Method to determine the speckle characteristics of front projection screens

Falko Riechert, Felix Glöckler, and Uli Lemmer
Appl. Opt. 48(7) 1316-1321 (2009)

Low-loss high-speed speckle reduction using a colloidal dispersion

Brandon Redding, Graham Allen, Eric R. Dufresne, and Hui Cao
Appl. Opt. 52(6) 1168-1172 (2013)

Efficient speckle reduction for a laser illuminating on a micro-vibrated paper screen

Shih-Yu Tu, Hoang Yan Lin, and Min-Ching Lin
Appl. Opt. 53(22) E38-E46 (2014)

Low-speckle laser projection with a broad-area vertical-cavity surface-emitting laser in the nonmodal emission regime

Falko Riechert, Gordon Craggs, Youri Meuret, Bart Van Giel, Hugo Thienpont, Uli Lemmer, and Guy Verschaffelt
Appl. Opt. 48(4) 792-798 (2009)

Speckle reduction in laser projection using microlens-array screens

Jaël Pauwels and Guy Verschaffelt
Opt. Express 25(4) 3180-3195 (2017)