Exhibit 31.1
CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO
EXCHANGE ACT RULE 13a-14(a)
I, John R. Ambroseo, certify that:
1. I have reviewed this Annual Report on Form 10-K/A of Coherent, Inc.;
2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;
Date: February 1, 2010
| By: | /s/ JOHN R. AMBROSEO |
|
| John R. Ambroseo |
|
| President and Chief Executive Officer |
