Geometric Theory of Lattice Vibrations and Specific Heat

A scanning system for linearized application of an energy beam along at least one of a plurality of predetermined axes. Chopper means intercept the energy beam for alternately reflecting and passing the energy beam providing successive reflective and passed beams respectively therefrom. First and second scanning means receive the reflected and passed beams respectively. The first and second scanning means synchronously direct the reflected and passed beams along at least one of the predetermined axes.