Abstract

In laser projection systems the observer in the far field of the image points on the screen will recognize serious speckle noise. There are many methods to reduce or eliminate speckles in the near field by reducing or eliminating temporal or spatial coherence of the laser. But for the far field it is hardly possible to change the coherence properties of laser sources so that speckles will disappear. We propose a new method for eliminating speckles in the far field by using a diffractive optical element. The intensity modulation depth in the far-field speckle pattern can be reduced to a few percent while good beam quality is preserved.

© 1998 Optical Society of America

Laser speckle reduction via colloidal-dispersion-filled projection screens

Falko Riechert, Georg Bastian, and Uli Lemmer
Appl. Opt. 48(19) 3742-3749 (2009)

High speckle reduction rate in a laser projection system

Yue-Xun Song and Jui-Wen Pan
Appl. Opt. 60(34) 10564-10569 (2021)

Low speckle laser illuminated projection system with a vibrating diffractive beam shaper

Po-Hung Yao, Chieh-Hui Chen, and Cheng-Huan Chen
Opt. Express 20(15) 16552-16566 (2012)

Speckle reduction in laser projection using microlens-array screens

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

Speckle suppression in scanning laser displays: aberration and defocusing of the projection system

Victor Yurlov, Anatoly Lapchuk, Sangkyeong Yun, Jonghyeong Song, Injae Yeo, Haengseok Yang, and Seungdo An.
Appl. Opt. 48(1) 80-90 (2009)