Abstract
Infrared light scattering tomography combined with infrared absorption imaging is developed for characterization of semi-insulating GaAs crystals to take simultaneously both the IR absorption and light scattering images. Very close correlation of many dislocation lines and point defects was found between these images in a semi-insulating In-doped LEC GaAs crystal grown from a stoichiometric melt, while a few dislocation lines showed only light scattering of 1.15 µm laser beam.