A device for directing radiation to a layer (1) is described. The device
includes a first optical element (L1) for focusing a first radiation beam
(B1) originating from a first radiation source (S1) onto said layer, a
second optical element (L2) for focusing a second radiation beam (B2)
originating from a second radiation source (S2) onto said layer. The
wavelengths of the radiation from said first and said second radiation
source are different from each other. The first and second optical
element are jointly movable with respect to said radiation sources,
wherein the focal points of the two radiation beams at least
substantially coincide with various movements of the first optical
element and the second optical element with respect to the radiation
sources. The second optical element (L2) has an aperture (A2) which
allows optically undisturbed passage of the first radiation beam (B1). In
this way a compact and light configuration of L1 and L2 is achieved as
well as an improved radiation beam quality. Further an apparatus
comprising such a device and a method using such an apparatus are
disclosed.