Abstract

Forsterite is a crystalline magnesium silicate with chemical formula Mg₂SiO₄, which has extremely low electrical conductivity that makes it an ideal substrate material for tunable laser. Forsterite single crystals doped with tetravalent chromium ions, Mg₂SiO₄:Cr⁴⁺, are widely used as active media of solid-state lasers tunable in the range of 1.13–1.37 µm [1] and mode-locked lasers generating ultrashort pulses [2]. Additional doping of Mg₂SiO₄:Cr crystals with lithium makes it possible to tune solid-state lasers in the spectral range of 1.03–1.18 µm [3]. Different procedures have been used to prepare forsterite ceramics, such as solid-state reactions and sol-gel techniques. However, they are complex and costly. Forsterite can be formed by thermal decomposition of serpentine minerals, Mg₃Si₂O₅(OH)₄, which are widespread in the world. This method requires high temperature (~ 900 °C), and additives were added to reduce the decomposition temperature and thus the cost associated with high temperature processes [4]. Solar power is the ultimate renewable energy source. High temperature solar furnaces have been used for the production of many types of products. With a heliostat-parabolic mirror solar energy collection and concentration system, the sample in the focal zone can be heated from ambient temperature to very high temperature within seconds. To the best of our knowledge, we report here the first use of solar furnace for the production of forsterite from serpentine. Compared with other existing processes, this renewable, simple, fast and cost-effective method constitutes a very effective alternative to forsterite production.

© 2015 IEEE