Multispectral glass transparent from visible to thermal infrared

摘要

The thermal imaging market has experienced a strong growth during the recent years due to continued cost reduction of night vision devices. The development of uncooled focal plane detector arrays is the major reason for the cost reduction. Another reason is the continuous improvement of the optical solution. In this paper, we present a new multispectral material which responds to the increasing demand for optics operating simultaneously in the visible/SWIR (Short Wave InfraRed) and the thermal infrared region. The most important properties of some glasses from the GeS_2-Ga_2S_3-CsCl system are highlighted in this study. A stable composition 15Ga_2S_3-75GeS_2-10CsCl allowed the synthesis of a large glass without crystallization. The refractive index of this glass was precisely measured from 0.6 to 10.4μm by using the Littrow method. The chromatic dispersion was then calculated and compared with other multispectral materials.