A goniometer includes a base, a compound member supported by the base, a light-directing element operably mounted on the compound member, optically connected to a coherent light source, and disposed toward an optical filter, a first actuator disposed along a first axis and operably coupled to the base for translating the light-directing element along a first arcuate path disposed in a first plane; and a second actuator disposed along a second axis and operably coupled to the compound member for translating the light-directing element along a second arcuate path disposed in a second plane, wherein the first plane is orthogonal to the second plane, and wherein the first and second axes are co-planar, for directing coherent light at an angle that is normal to the optical filter.