Abstract

Gallium-lanthanum sulphide (Ga₂S₃-La₂ S₃) (GLS) glasses have a range of novel optoelectronic applications. The material is transparent from ~0.65 μm to ~10 μm, covering the important near-infrared telecommunications and mid-infrared 'fingerprint' spectral regions. The lanthanum content ensures very high solubility for other rare-earth dopant ions such as Er³⁺, Ho³⁺, Fr³⁺, Nd³⁺, etc., which can be used as active laser or optical amplifier species. The low phonon energy of GLS glass gives rise to low nonradiative relaxation rates, which opens the possibility of operating lasers in this host material in the mid-infrared. Laser action to wavelengths approaching 5 pm may be feasible in high-quality films. An unusual property of the material is that the refractive index can be substantially and permanently modified by over 1% by exposure to illumination above the band gap, typically at 0.5145 μm wavelength or shorter.

© 1996 Optical Society of America