(19)

(11)

EP 0 837 835 A1

(12)

(43) Date of publication: 29.04.1998 Bulletin 1998/18 (21) Application number: 96924085.0 (22) Date of filing: 15.07.1996

(51) International Patent Classification (IPC):  C03C 3/ 32( . ) C03C 13/ 04( . ) H01S 3/ 10( . ) C03C 4/ 00( . ) H01S 3/ 06( . ) (86) International application number: PCT/GB1996/001692 (87) International publication number: WO 1997/003028 (30.01.1997 Gazette 1997/06)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 13.07.1995 GB 19950014345 (71) Applicant: BRITISH TECHNOLOGY GROUP LIMITED London EC4M 7SB (GB)	(72) Inventors: JHA, Animesh-The School of Materials Leeds LS2 9JT (GB) MARCHESE, Diego I-70125 Bari (IT) KAKARANTZAS, George GR-211 00 Nafplio (GR) (74) Representative: Cullis, Roger  Patents Department British Technology Group Ltd 10 Fleet Place London EC4M 7SB London EC4M 7SB (GB)