Multispectral glass transparent from visible to thermal infrared
Résumé
The thermal imaging market has experienced a strong growth during the recent years due to continued cost redn. of night vision devices. The development of uncooled focal plane detector arrays is the major reason for the cost redn. Another reason is the continuous improvement of the optical soln. 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 IR) and the thermal IR region. The most important properties of some glasses from the GeS2-Ga2S3-CsCl system are highlighted in this study. A stable compn. 15Ga2S3-75GeS2-10CsCl allowed the synthesis of a large glass without crystn. 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 calcd. and compared with other multispectral materials.