Coherent 10-K/A 2007 FY Annual report (amended)

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Exhibit 31.2

CERTIFICATION OF CHIEF FINANCIAL OFFICER PURSUANT TO
EXCHANGE ACT RULE 13a-14(a)

I, Helene Simonet, 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 12, 2008

By: /s/  HELENE SIMONET      Helene Simonet
Executive Vice President and Chief Financial Officer

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CERTIFICATION OF CHIEF FINANCIAL OFFICER PURSUANT TO EXCHANGE ACT RULE 13a-14(a)