Sapphire’s hardness, strength, and UV-IR transmittance make it an excellent candidate for IR window and transparent armor applications. At Saint-Gobain Crystals, Edge-defined Film-fed Growth (EFG) sapphire crystals are currently being manufactured for IR window and transparent armor applications in sizes up to 305x510x11 mm. However, the demand for even larger sapphire panels continues to increase. In order to aid in the development of larger pieces, a nondestructive measurement has been developed to map planar stress in Clear Large Area Sapphire Sheet (CLASS). The measurement works by utilizing optical excitation of trace amounts of Cr3+ impurities. The resulting luminescence produces a sharp emission doublet whose exact wavelength is dependent on spacing between Cr3+ and O2- ions in sapphire, and therefore the strain in the sample. By recording several data points over an array, it is possible to construct a stress map of large sapphire sheets and gain valuable information on the growth conditions of the sapphire ribbon.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.