STOCK PURCHASE AGREEMENT by and among BRUKER BIOSCIENCES CORPORATION (as “Purchaser”) and BRUKER OPTICS INC. (as the “Company”) and DIRK D. LAUKIEN FRANK H. LAUKIEN ISOLDE LAUKIEN JOERG C. LAUKIEN MARC M. LAUKIEN ROBYN L. LAUKIEN ARNO SIMON THE DIRK...