Measurement Settings for Speckle Characterization in Laser Displays
M-F. Xu, W-H. Gao, Y-B. Shi, J. Liu and X-Y. Chen
Speckle noise is a major limitation for laser to be used in display technology. Experimental set-up and measurement parameters strongly affect the speckle characterization. In this paper we present different experimental settings for characterizing the laser speckle. The affects of the intensity of incident light and camera settings, such as gamma value, exposure time and F/#, on speckle measurement are experimentally analysed. The effect due to inappropriate intensity of incident light decreases as the ratio of the maximum intensity and the mean intensity of all intensity values in the speckle pattern increases. For a nonlinear charge-coupled device (CCD) camera, measured mean intensities are more sensitive to gamma settings of CCD than measured standard deviations. Achieved results can make a good contribution for setting up a standard for speckle measurement in laser display technology.
Keywords: Laser speckle, laser displays, speckle contrast, gamma value, speckle characterization