A method and apparatus involve: routing first radiation and second radiation respectively having first and second wavelengths that are different along respective first and second optical paths; reflecting the first radiation with an optical component as the first radiation is traveling along the first optical path; and reflecting the second radiation with the optical component as the second radiation is traveling along the second optical path, the optical component causing a first optical path length traveled by the first radiation along the first optical path from arrival at to departure from the optical component to be shorter than a second optical path length traveled by the second radiation along the second optical path from arrival at to departure from the optical component.