A Review of Light Sources Used for Laser Speckle Suppression

Laser speckle is greatly influenced by the chosen light source and how or if its emission is manipulated. A laser without direct or posthumous speckle suppression techniques generates high speckle contrast (the quantitative measure of speckle) leading to low image fidelity. However, by destroying the laser’s temporal or spatial coherence and/or applying beam diversity, speckle contrast can be reduced whilst retaining many of the benefits of low power laser illumination in full-field and scanning applications. Thus, careful consideration of the choice of light source and speckle suppression method is critical. This Review summarizes the light sources commonly used by researchers in speckle suppression applications. Conclusions about which sources are most suitable for speckle suppression are drawn.