P‐17.2: Study on speckle suppression of RGB color semiconductor laser driven by high frequency current

The suppression of laser speckle has always been a crucial research topic in the field of laser display. At present, many methods of laser speckle suppression have been proposed. In this paper, we present a method for reducing speckle in high‐frequency current driven RGB semiconductor lasers. The RGB monochromatic speckle contrast in direct current (DC) driving mode and 100 Hz to 50 MHz pulse modulation frequency driving mode, and the color luminosity speckle contrast of composite light in 1 KHz to 45 MHz pulse modulation frequency driving mode were measured. Red laser speckle contrast is reduced from 47.12% to 38.5%, Green laser speckle contrast is reduced from 35.69% to 21%, and blue laser speckle contrast is reduced from 31.5% to 25.09%. Additionally, the photometric speckle contrast of composite light decreased by approximately 6%. Experimental results demonstrate that high‐frequency current driving mode disrupts the coherence of lasers and effectively suppresses both monochromatic and color‐based laser speckles.