Open AccessEffect of structure and size of laser spot on speckle contrast in laser scanning display
Author(s) -
Hong Chang,
Fugui Yang,
Lei Dong,
Anting Wang,
Jing Xie,
Hai Ming
Publication year - 2010
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.59.4634
Subject(s) - speckle pattern , optics , laser , materials science , contrast (vision) , specular reflection , scattering , laser scanning , physics
Speckle contrast in laser scanning display system with circular and rectangular laser spot on screen was calculated. For scanning with circular laser spot, the speckle contrast reduces with the decrease of the diameter of laser spot when the diameter of the laser spot is lager than the correlation length of the screen. When the laser spot is about the same size of the correlation length of the screen, the speckle contrast becomes higher owing to the non-Gaussian speckle effect. If we continue to reduce the size of laser spot, because of the specular reflection the speckle contrast decreases quickly. To ensure enough scattering elements in laser spot, the laser spot is just narrowed in one direction. If the laser spot is narrowed in the scanning direction, the speckle contrast is reduced due to the reducing temporal correlation of speckle, while if the laser spot is narrowed in the other direction, speckle contrast changes slightly. For the circular laser spot, some experimental results are given.