Homogeneous and speckle-free laser illumination for range-gated imaging and active polarimetry

We present simple illumination devices with built-in speckle reduction using the spatial diversity approach. These devices are based on a waveguide homogenization technique with a transmission efficiency of up to 95%. Even for single-laser pulse illumination from a solid-state laser source a reduction of the speckle contrast by a factor of 4.5 was demonstrated. In detail, we present two different illumination devices based on either a solid-state laser source or an array of semiconductor laser diodes. These illumination devices are used for range-gated imaging and active polarimetry with speckle-free and homogeneous illumination.