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(11)

EP 2 791 618 A2

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(88) Date of publication A3: 19.09.2013 (43) Date of publication: 22.10.2014 Bulletin 2014/43 (21) Application number: 11879165.6 (22) Date of filing: 12.12.2011

(51) International Patent Classification (IPC):  G01B 11/24(2006.01) G02B 27/22(2006.01) (86) International application number: PCT/US2011/064417 (87) International publication number: WO 2013/105922 (18.07.2013 Gazette 2013/29)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (71) Applicant: Zygo Corporation Middlefield, CT 06455-0448 (US)	(72) Inventor: COLONNA DE LEGA, Xavier M. Middlefield, Connecticut 06455 (US) (74) Representative: Schley, Jan Malte et al Fish & Richardson P.C. HighLight Business Towers Mies-van-der-Rohe-Str. 8 80807 München 80807 München (DE)