Compound Speckle Characterization Method and Reduction by Optical Design

Author

Tong, Zhaomin ; Chen, Xuyuan ; Akram, Muhammad Nadeem ; Aksnes, Astrid

Author_Institution

Inst. for Microsyst. Technol., Vestfold Univ. Coll., Borre, Norway

Volume

8

Issue

3

fYear

2012

fDate

3/1/2012 12:00:00 AM

Firstpage

132

Lastpage

137

Abstract

Speckle and the compound speckle can be reduced by angle diversity. In laser projection displays, simple, low cost and efficient speckle reduction techniques require smart optical design . Using a MEMS scanner together with a condenser lens, laser beams with different illumination angles are obtained on the diffuser surface with low speckle contrast ratio (CR). After homogenizing within a rod integrator, the speckle field illuminates a display panel, and is projected onto the screen which forms the compound speckle. Characterization method to evaluate the compound speckle reduction efficiency is analyzed and discussed in a simplified optical system. The preliminary speckle reduction is demonstrated in a commercial projector where a 600 mW green laser has been used as the illumination source, and the compound speckle CR is brought down from 0.38 to 0.14.

Keywords

colour displays; laser beams; lasers; lenses; micromechanical devices; optical projectors; optical scanners; speckle; MEMS scanner; angle diversity; commercial projector; compound speckle characterization; compound speckle reduction efficiency; condenser lens; diffuser surface; green laser; illumination angle source; laser beam; laser projection display panel; low speckle CR; low speckle contrast ratio; power 600 mW; rod integrator; smart optical design; Adaptive optics; Compounds; Educational institutions; Lasers; Lenses; Optical imaging; Speckle; Angle diversity; compound speckle; laser projection displays; speckle reduction;

fLanguage

English

Journal_Title

Display Technology, Journal of

Publisher

ieee

ISSN

1551-319X

Type

jour

DOI

10.1109/JDT.2011.2168384

Filename

6145771