In another paper in these proceedings, Opsal [1] discusses the origin of the modulated reflectance signal observed in silicon under the experimental conditions employed in the Therma-Probe system [2]. These experimental conditions are described in the paper by Smith, Hahn and Arst in these proceedings [3]. Table I lists the major differences between our type of modulated optical reflectance experiments and the more conventional photoreflectance experiments [4–10].