(19)

(11)

EP 0 857 313 A1

(12)

(43) Date of publication: 12.08.1998 Bulletin 1998/33 (21) Application number: 97934929.0 (22) Date of filing: 14.07.1997

(51) International Patent Classification (IPC):  G02B 6/ 02( . ) G02B 6/ 036( . ) C03B 37/ 023( . ) H04B 10/ 18( . ) (86) International application number: PCT/US1997/012136 (87) International publication number: WO 1998/004941 (05.02.1998 Gazette 1998/05)

(84) Designated Contracting States: AT CH DE DK ES FR GB IT LI NL SE (30) Priority: 31.07.1996 US 19960023297P (71) Applicant: CORNING INCORPORATED Corning, N.Y. 14831 (US)	(72) Inventors: ANTOS, A., Joseph Elmira, NY 14903 (US) BERKEY, George, E. Pine City, NY 14871 (US) HAWTOF, Daniel, W. Painted Post, NY 14870 (US) HOLMES, G., Thomas Painted Post, NY 14870 (US) LIU, Yanming Horseheads, NY 14845 (US) (74) Representative: Boon, Graham Anthony  Elkington and Fife, Prospect House, 8 Pembroke Road Sevenoaks, Kent TN13 1XR Sevenoaks, Kent TN13 1XR (GB)