Abstract: The present invention provides a fluid purging system (100) for an optical element (120), comprising a fluid guiding unit arranged to guide a fluid, provided by a fluid supply system, over at least a curved portion of an optical surface (122) of the optical element. The fluid guiding unit comprises a fluid inlet and a first nozzle unit (110) for providing a fluid to the optical surface. The fluid guiding unit being formed by at least a first wall portion (102) and at least a second wall portion (104), wherein the second wall portion being configured to face the optical surface and to follow a contour of the optical surface. The second wall portion comprises a second nozzle unit (112).

Abstract: The present invention provides a fluid purging system (100) for an optical element (30), comprising a ring and a fluid supply system (40). The ring being formed of a body entirely surrounding the optical element, the ring defining a space (5) radially inwards thereof and adjacent to the optical element. The ring is formed by at least one first wall portion (10) and at least one second wall portion (20A;20B), wherein an average height of the first wall portion is greater than an average height of the second wall portion. The fluid supply system is positioned radially outwards of the ring and configured to supply fluid to pass over the at least one second wall portion to the space.