SCHEDULE 13D/A 0001910890 XXXXXXXX LIVE 6 Common Stock, no par value 02/09/2026 false 0000820318 19247G107 Coherent Corp.

375 Saxonburg Boulevard Saxonburg PA 16056

Bain Capital Investors, LLC 617-516-2000 200 Clarendon Street Boston MA 02116 0001910890 N BCPE Watson (DE) BML, LP WC N DE 0.00 0 0.00 0 0 N 0 PN Common Stock, no par value Coherent Corp. 375 Saxonburg Boulevard Saxonburg PA 16056 This Amendment No. 6 ("Amendment No. 6") to Schedule 13D amends and supplements the statement on Schedule 13D originally filed on July 11, 2022, as amended by Amendment No. 1 to Schedule 13D filed on March 7, 2024, Amendment No. 2 to Schedule 13D filed on November 12, 2025, Amendment No. 3 to Schedule 13D filed on November 24, 2025, Amendment No.4 to Schedule 13D filed on December 4, 2025, and Amendment No.5 to Schedule 13D filed on December 12, 2025 (the "Initial Statement", together with this Amendment No. 5, the "Schedule 13D"), with respect to shares of Common Stock, no par value (the "Common Stock"), of Coherent Corp., a Pennsylvania corporation (the "Issuer"). Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Initial Statement. Item 4 of the Initial Statement is hereby amended and supplemented to add the following: Sale of Common Stock On February 9, 2026, the Reporting Person sold 9,437,238 shares of Common Stock in a block trade pursuant to Rule 144 of the Securities Act of 1933 at a price of $235.58 per share, for an aggregate amount of $2,223,224,528.04. In connection with the settlement of the block trade, the Reporting Person intends to distribute an aggregate of 338,608 shares of Common Stock to one or more members or partners of the Reporting Person in connection with certain charitable gifts to be made by such members or partners or their direct and indirect owners, for no consideration. The information contained in rows 7, 8, 9, 10, 11 and 13 on the cover page of this Schedule 13D and the information set forth or incorporated in Items 2, 3, 4 and 6 is incorporated by reference in its entirety into this Item 5. The information contained in rows 7, 8, 9, 10, 11 and 13 on the cover page of this Schedule 13D and the information set forth or incorporated in Items 2, 3, 4 and 6 is incorporated by reference in its entirety into this Item 5. Except as described in this Schedule 13D, the Reporting Person has not effected any transactions in the Common Shares during the past sixty days. Except as otherwise described in this Schedule 13D, no one other than the Reporting Person has the right to receive, or the power to direct the receipt of, dividends from, or the proceeds from the sale of, any of the Common Stock beneficially owned by the Reporting Persons as described in this Item 5. February 9, 2026 BCPE Watson (DE) BML, LP /s/ Joseph Robbins 02/11/2026