The laser damage threshold of KDP crystals is one major limitation in many high-power laser systems. Investigation of laser damage behavior of KDP crystals shows that the major reason for laser damage is the growth defects in the bulk of the materials. Therefore, an effective diagnostic method for those defects is quite necessary for producing KDP crystals with high enough damage threshold to meet the requirement of high power laser applications. In this paper, we reported the characterization of bulk defects in KDP crystals using a three dimensional photothermal microscope based on a laserinduced photothermal lensing technique. Several 3D mapping of the bulk defects were obtained. The results indicated that both surface defects and bulk defects can be determined and analyzed using the 3-D photothermal microscope. The details of the development of the 3-D photothermal microscope were also presented. The system provided user-friendly operations of the defects characterization process and showed great potential of application for characterization of low absorption optical materials.

Date Published: 18 August 2014
PDF: 6 pages
Proc. SPIE 9203, Interferometry XVII: Techniques and Analysis, 92030W (18 August 2014); doi: 10.1117/12.2062528

Published in SPIE Proceedings Vol. 9203:
Interferometry XVII: Techniques and Analysis
Katherine Creath; Jan Burke; Joanna Schmit, Editor(s)