(19)

(11)

EP 1 088 248 A1

(12)

(43) Date of publication: 04.04.2001 Bulletin 2001/14 (21) Application number: 00926004.3 (22) Date of filing: 17.04.2000

(51) International Patent Classification (IPC)7: G02B 5/28 (86) International application number: PCT/US0010/072 (87) International publication number: WO 0063/728 (26.10.2000 Gazette 2000/43)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 20.04.1999 US 130212 P (71) Applicant: Ciena Corporation Linthicum, MD 21090 (US)	(72) Inventors: ARCHAMBAULT, Jean-Luc Severna Park, MD 21146 (US) PELEKHATY, Vladimir Baltimore, MD 21208 (US) (74) Representative: Jeffrey, Philip Michael  Frank B. Dehn & Co.179 Queen Victoria Street London EC4V 4EL London EC4V 4EL (GB)