Making impurities free glass ceramic, useful in wavelength converter, comprises melting glass having oxides of silicon, aluminum, yttrium, lutetium, scandium, gadolinium, ytterbium, lanthanide and boron, and heating obtained oxide mixture

摘要

Preparing a glass ceramic (I) comprises melting a glass (T) containing (in wt.%): silicon dioxide (5-50); aluminum oxide (5-50); a mixed oxide compound (10-80) of yttrium-, lutetium-, scandium-, gadolinium- and ytterbium oxides; an oxide compound (0.1-30) e.g. lanthanide- or boron oxide, and heating the obtained oxide mixture at a heating rate of 10 K/minute using infra-red radiation at 1000-1400[deg]C, preferably 1150-1250[deg]C to form a ceramic crystals containing a garnet phase, and cooling the obtained ceramic at ambient temperature. Independent claims are included for: (1) (I) prepared by the process; and (2) a process of manufacturing a wavelength converter comprising using (I), where the wavelength converter is useful for converting a first radiation in to a radiation of different energy or in to a spectral distribution, particularly converting excited radiation to UV and blue spectral regions.