Speckle Suppression by Chaotic Laser in Laser Display

We use the chaotic laser with low coherence property to achieve speckle suppression. In particular, we use laser diodes commonly used in laser display to generate chaotic laser by diodes with optical feedback perturbation and diodes with electrical chaotic signal modulation. The effects of bias current and feedback strength in the optical feedback system, and the bias current and modulation amplitude in the modulation system on speckle suppression are studied, respectively. Moreover, the speckle suppression effects of two systems are compared. The experimental results show that the chaotic laser generated by two methods effectively suppresses the speckle noise, and the speckle contrast of speckle patterns is reduced by more than 0. 9, the maximum spectrum can be expanded to 4. 6 nm by using chaotic laser, and the coherence length is reduced from 441 mu m to 87 mu m.