Microlens arrays contain multiple lenses formed in a one-dimensional or two-dimensional array on a supporting substrate. With optical sensor arrays tiny lens systems serve to focus and concentrate the light onto the photodiode surface instead of allowing it to fall on non-photosensitive areas of the pixel device. Fill-factor area occupied by the microlens arrays. Mostly, the lens shape is cylindrical or spherical. Array size strongly depends on the applications. It can range from 1x2 for optical switch applications up to more than 103x103 for diffusers or display applications. Single...