A microscopic fluorescence imaging system is used to detect optically active centers located inside a transparent dielectric crystal. Defect centers in the bulk of KH<sub>2</sub>PO<sub>4</sub> crystals are imaged based on their near-infrared emission following photoexcitation. The spatial resolution of the system is 1μm in the image plane and 25μm in depth. The experimental results indicate the presence of a large number of optically active defect clusters in different KH<sub>2</sub>PO<sub>4</sub> crystals, whereas the concentration of these clusters depends on the crystal sector and growth method.
© 1999 Optical Society of America
(160.4330) Materials : Nonlinear optical materials
(180.2520) Microscopy : Fluorescence microscopy
(300.2530) Spectroscopy : Fluorescence, laser-induced
(300.6250) Spectroscopy : Spectroscopy, condensed matter
S. G. Demos, M. Staggs, M. Yan, H. B. Radousky, and J. J. De Yoreo, "Microscopic fluorescence imaging of bulk defect clusters in KH2PO4 crystals," Opt. Lett. 24, 268-270 (1999)