A passive optical component directs first electromagnetic radiation incident on the component in a first direction and second electromagnetic radiation incident on the component in a second direction to a mutual direction. The optical component comprises an interacting surface which is arranged to interact with said first and second electromagnetic radiation. The interacting surface comprises first portions, each having a surface extending in a third direction, which is essentially perpendicular to the mutual direction, and second portions, each having a surface extending in a fourth direction. The optical component reflects essentially all the first electromagnetic radiation and transmits at least a significant portion of the second electromagnetic radiation for directing the first and the second electromagnetic radiation to a mutual direction. An optical system and a method using the passive optical component are also shown.