The existence of defects in lithium niobate degrades the specific properties required of LiNbO3 as substrate material, which was a major problem inhibiting device construction. For the purpose of providing a convenient and quick tool for use in a non-destructive testing technique for defect detection, the feasibility of using an infra-red thermal imaging camera was examined by comparing the results of infra-red camera use with those of scanning laser microscopy and light-scattering tomography. Success was had in the detection of defects in the LiNbO3 substrate by observing the thermal properties of defects in a relatively wide field of view (8mm x 6mm) as compared with using conventional microscopes. The maximum temperature difference of the defects in the LiNbO3 substrate was 0.47K.

Nondestructive Testing Technique for Defect Detection in LiNbO3 Using Infrared Thermal Imaging Camera. K.Lee, H.Miyazaki, Y.Okamoto, J.Morimoto, K.Toda: Japanese Journal of Applied Physics, 2010, 49, 07HB07