The theory of speckle noise in a scanning beam is presented. The general formulas for the calculation of speckle contrast, which apply to any scanning display, are obtained. It is shown that the main requirement for successful speckle suppression in a scanning display is a narrow autocorrelation peak and low sidelobe level in the autocorrelation function of the complex amplitude distribution across a scanning light beam. The simple formulas for speckle contrast for a beam with a narrow autocorrelation function peak were obtained. It was shown that application of a diffractive optical element (DOE) with a Barker code phase shape could use only natural display scanning motion for speckle suppression. DOE with a Barker code phase shape has a small size and may be deposited on the light modulator inside the depth of the focus of the reflected beam area, and therefore, it does not need an additional image plane and complicated relay optics.
© 2008 Optical Society of America
Coherence and Statistical Optics
Original Manuscript: September 19, 2007
Revised Manuscript: November 16, 2007
Manuscript Accepted: November 20, 2007
Published: January 8, 2008
Victor Yurlov, Anatoly Lapchuk, Sangkyeong Yun, Jonghyeong Song, and Haengseok Yang, "Speckle suppression in scanning laser display," Appl. Opt. 47, 179-187 (2008)