Exhibit 11 THERMO OPTEK CORPORATION Computation of Earnings per Share Three Months Ended ------------------------------- March 29, March 30, 1997 1996 -------------------------------------------------------------------------- Computation of Primary Earnings per Share: Net Income (a) $ 6,749,000 $ 4,296,000 ----------- ----------- Shares: Weighted average shares outstanding 48,450,000 45,000,000 Add: Shares issuable from assumed exercise of options (as determined by the application of the treasury stock method) - 157,040 ----------- ----------- Weighted average shares outstanding, as adjusted (b) 48,450,000 45,157,040 ----------- ----------- Primary Earnings per Share (a) / (b) $ .14 $ .10 =========== ===========