The Bridgman method growth and spectroscopic characterization of calcium fluoride single crystals

Abstract

It must be noted that the main objective of this study was to obtain single crystals of calcium fluoride -CaF 2 , and after that the crystals were characterized with various spectroscopic methods. The crystals were grown using the Bridgman technique. By optimizing growth conditions, <111> oriented CaF 2 crystals up to 20 mm in diameter were grown.Number of dislocations in CaF 2 crystals was 5×10 4 -2×10 5 per cm 2 . Selected CaF 2 single crystal is cut into several tiles with the diamond saw. The plates were polished, first with the silicon carbide, then the paraffin oil, and finally with a diamond paste. The obtained crystal wаs studied by Raman and infrared -IR spectroscopy. The crystal structure is confirmed by Xray diffraction (XRD). One Raman and two IR optical modes predicted by group theory are observed. A low photoluminescence testifies that the concentration of oxygen defects within the host CaF 2 is small. All performed investigations show that the obtained CaF 2 single crystal has good optical quality, which was the goal of this work.

Characterization of neodymium doped calcium tungstate single crystal by Raman, IR and luminescence spectroscopy

“…The infrared reflectivity measurements were performed at room temperature with a BOMEM DA-8 Fourier-transform infrared spectrometer [31]. A hyper beamsplitter and deuterated triglycine sulfate (DTGS) pyroelectric detector were used to cover the wavenumber region from 80 to 650 cm -1 .…”