US Patent 10185154 Laser despeckler based on angular diversity

A device for reducing laser speckle using a micro scanner and a holographic diffuser. The micro scanner includes a first transparent optical substrate with an input surface and an output surface and a second transparent optical substrate with an input surface and an output surface and a variable refractive index medium sandwiched between the output surface of the first substrate and the input surface of the second substrate. Transparent electrodes are applied to the output surface of the first substrate and the input surface of the second substrate. The electrodes are coupled to a voltage generator. The input surface of the first substrate is optically coupled to a laser source. The input surface of the second substrate is configured as an array of prismatic elements. At least one of the input surface of the first substrate or the output surfaces of the second substrate is planar.