Speckle suppression in projection displays by using a motionless changing diffuser

Speckle suppression in projection displays with the laser light source can be achieved by imaging a changing diffuser with random phase cells onto the screen. Theoretical expressions for the speckle contrast in this method have been earlier obtained in the case when different realizations of the phase diffuser produce statistically independent patterns of the light field on the screen [J. W. Goodman]. In the present paper, these expressions are generalized in the case when different realizations of the phase diffuser produce partly correlated speckle patterns. Both cases when the diffuser just fills or overfills the projection optics are considered. Possible structure of a motionless changing diffuser is presented. It includes the dynamic diffractive optical element (DDOE) and a light homogenizer. The DDOE can be based on the electrically controlled spatial light modulator with a deformable polymer layer (SLMDPL). The SLMDPL can handle high light power and therefore, can be used in projection displays with powerful laser beams.

[1]  Benny Svardal,et al.  Image improvement in a laser projection display with a spatial light modulator with a deformable polymer , 2009 .

[2]  J. Goodman.  Introduction to Fourier optics , 1969 .

[3]  T. Tschudi,et al.  Speckle reduction in laser projection systems by diffractive optical elements. , 1998, Applied optics.

[4]  Victor Yurlov,et al.  Speckle suppression in scanning laser display. , 2008, Applied optics.

[5]  Victor Yurlov,et al.  Speckle suppression in scanning laser displays: aberration and defocusing of the projection system. , 2009, Applied optics.

[6]  N George,et al.  Speckle reduction using multiple tones of illumination. , 1973, Applied optics.

[7]  Yasuo Kitaoka,et al.  A practical laser projector with new illumination optics for reduction of speckle noise , 2004 .

[8]  Denis Joyeux,et al.  Speckle Removal by a Slowly Moving Diffuser Associated with a Motionless Diffuser , 1971 .

[9]  J. Goodman.  Speckle Phenomena in Optics: Theory and Applications , 2020 .

[10]  Jahja I. Trisnadi.  Hadamard speckle contrast reduction. , 2004, Optics letters.

[11]  Lingli Wang,et al.  Speckle reduction in laser projections with ultrasonic waves , 2000 .

[12]  Zhaomin Tong,et al.  Speckle reduction in line-scan laser projectors using binary phase codes. , 2010, Optics letters.

[13]  Jahja I. Trisnadi.  Speckle contrast reduction in laser projection displays , 2002, IS&T/SPIE Electronic Imaging.

[14]  Itay Peled,et al.  MEMS based speckle reduction obtain by angle diversity for fast imaging , 2009, 2009 Conference on Lasers and Electro-Optics and 2009 Conference on Quantum electronics and Laser Science Conference.