For absorption measurement of large-aperture optical coatings, a novel method of imaging photothermal microscopy based on image lock-in technique is presented. Detailed theoretical analysis and numerical calculation are made based on the image photothermal technique. The feasibility of this imaging method is proved through the coincidence between the theoretical results of single spot method and multi-channel method. The measuring speed of this imaging method can be increased hundreds of times compared with that of the raster scanning. This technique can expand the applications of photothermal technique.
© 2009 Chinese Optics Letters
Chunxian Tao, Yuanan Zhao, Hongbo He, Dawei Li, Jianda Shao, and Zhengxiu Fan, "Imaging photothermal microscopy for absorption measurements of optical coatings," Chin. Opt. Lett. 7, 1061-1064 (2009)