| abstract |
The active medium of a laser comprises a glass containing from 0.01 to 30% of a fluorescent material, the term glass being used to mean any transparent non-crystalline, organic or inorganic host material. The fluorescent material may be one or more of the elements neodymium+++, praseodymium+++, samarium++, samarium+++, europium++, europium+++, uranium+++, terbium+++, holmium+++, erbium+++, thulium+++, dysposium+++, ytterbium+++ and cerium+++. The doping material may be added to organic glasses either as free ions or as compounds such as neodymium acetate, neodymium chloride or neodymium chelate. The host material may be a true glass such as schott glass, soda lime glass, barium crown glass, flint glass, lead glass or arsenic trisulphide glass. Other true glasses are sodium borate, aluminium zinc phosphate, lead silicate, sodium borosilicate, germanate and beryllium fluoride glass. Alternatively, the host material may be an organic glass including plastics solid at room temperature such as methyl methacrylate, acrylics and vinyl chlorides. Other glassy materials are glycerine and other devitrified sugar substances, or mixtures of organic solutions which form clear solid glasses when cooled to a low temperature such as E.P.A. (ether, isopentan and alcohol). |