Speckle reduction using a motionless diffractive optical element.

Speckle reduction by moving diffuser has been previously studied in display systems with coherent light sources, such as lasers. In this Letter, we propose a motionless diffractive optical element (DOE) for speckle reduction. The DOE was designed based on finite-element method simulations, fabricated using micromachining technology, and characterized for despeckle efficiency.

Laser speckle reduction due to spatial and angular diversity introduced by fast scanning micromirror.

We utilize spatial and angular diversity to achieve speckle reduction in laser illumination. Both free-space and imaging geometry configurations are considered. A fast two-dimensional scanning micromirror is employed to steer the laser beam.