Glasses for optoelectronics II : 12-14 March 1991, the Hague, the Netherlands : proceedings : ECO4, the congress of EPS--European Physical Society, EUROPTICA--the European Federation for Applied Optics, SPIE--the International Society for Optical Engineering - Righini, Giancarlo C. (Proceedings of SPIE--the International Society for Optical Engineering ;, 1991)