The invention concerns a light filter comprising a plate defined by a length along a direction x, a width along a direction y and a height along a direction z said plate including at least one chamber containing Liquid Crystals (LC) molecules and which is oriented substantially along a direction parallel to the xy, xz or yz-plane said filter furthermore being adapted to let a flow be present or temporally and spatially modified within said chamber, wherein said LC molecules are oriented along a first direction in the absence of said flow and along second direction when said flow is present, resulting thus in the emergence or modification of a birefringence. The invention also relates to a method for using this light filter.