EX-23.1 28 b61608s1exv23w1.txt EX-23.1 CONSENT OF DELOITTE & TOUCHE LLP EXHIBIT 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the use in this Registration Statement on Form S-1 of our report dated July 5, 2006, relating to the financial statements of IPG Photonics Corporation and subsidiaries appearing in the Prospectus, which is part of this Registration Statement. We also consent to the reference to us under the heading "Experts" in such Prospectus. /s/ DELOITTE & TOUCHE LLP Boston, Massachusetts August 11, 2006