A spectral splitting component is provided, having two faces, a planar front face comprising a dichroic treatment and a back face. It is intended to be placed downstream of a convergent objective. The back face is convex and forms a cylindrical surface defined by a generatrix of fixed direction moving perpendicularly along a circular arc comprising two ends, the plane passing through these two ends and parallel to the generatrix of the cylindrical surface forming a dihedral with the plane of the front face, the generatrix of the cylindrical surface being parallel to the edge of the dihedral.