Item 1.01 Entry into a Material Definitive Agreement. On November 27, 2025, Prime World International Holdings, Ltd. (“ Prime World”), a wholly owned subsidiary of Applied Optoelectronics, Inc., entered into a credit facility with Taishin International Bank in Taiwan (the “ Bank”), consisting of a NT$100,000,000 line of credit (the “ NT$100M Credit Line”) and a US$2,000,000 line of credit (the “ US$2M Credit Line”, collectively, with the NT$100M Credit Line, the “ Credit Facility”). Prime World may utilize the Credit Facility from November 27, 2025 through October 31, 2026. Borrowings under the NT$100M Credit Line may be drawn as short-term loans, each with a three-month draw term. The current interest rate is approximately 2.5%, but the rate for each draw remains subject to separate negotiation, and the facility may be used on a revolving basis. Interest on outstanding borrowings will be payable monthly, and all principal amounts will be due at the end of the applicable draw term. In contrast, the US$2M Credit Line is a derivatives-based facility rather than a loan facility and may be used by Prime World to enter into foreign exchange hedging transactions, including the Bank’s foreign-exchange-linked products. Pricing for each hedging transaction will be determined based on the Bank’s prevailing foreign exchange rates or quoted terms at the time the transaction is executed. Prime World’s obligations under the Credit Facility will be secured by a promissory note executed between Prime World and the Bank. The agreements for the Credit Facility contain representations and warranties, and events of default applicable to Prime World that are customary for agreements of this type. The foregoing description of the Credit Facility does not purport to be a complete statement of the parties’ rights and obligations under the Credit Facility and is qualified in its entirety by reference to the translation of the full text of the Approval Notice of Credit Line, General Agreement for Financial Transaction, Loan Agreement, and Promissory Note which are attached as Exhibit 10.1 through 10.4 to this Current Report on Form 8-K and are incorporated by reference herein.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation The information contained in Item 1.01 of this Current Report on Form 8-K with respect to the Credit Facility is incorporated by reference herein and made a part hereof.

Item 9.01. Financial Statements and Exhibits. (d) Exhibits Exhibit No. Description 10.1 Translation of the Approval Notice of Credit Line, dated October 20, 2025. 10.2 Translation of the General Agreement for Financial Transaction, dated November 27, 2025, between Prime World International Holdings Ltd. and Taishin International Bank. 10.3 Translation of the Loan Agreement, dated November 27, 2025, between Prime World International Holdings Ltd. and Taishin International Bank. 10.4 Translation of the Promissory Note, dated November 27, 2025, between Prime World International Holdings Ltd. and Taishin International Bank. ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 104 Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document). 2 SIGNATURES