AAOI · Quarterly Report (Form 10-Q) · Filed November 6, 2025

Applied Optoelectronics Inc — 10-Q exhibit

ex_854175.htm

Applied Optoelectronics Inc on Boardroom Alpha

ex_854175.htm

Exhibit 32.1

Certification

Pursuant to the requirement set forth in Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and Section 1350 of Chapter 63 of Title 18 of the U.S. Code (18 U.S.C. § 1350), Chih-Hsiang (Thompson) Lin, President and Chief Executive Officer of Applied Optoelectronics, Inc. (the “Company”), and Stefan J. Murry, Chief Financial Officer and Senior Vice President of the Company, each hereby certifies that, to the best of his knowledge:

The Company’s Quarterly Report on Form 10-Q for the period ended September 30, 2025, to which this Certification is attached as Exhibit 32.1 (the “Quarterly Report”) fully complies with the requirements of Section 13(a) or Section 15(d) of the Exchange Act; and

The information contained in the Quarterly Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

In Witness Whereof, the undersigned have set their hands hereto as of the 6th day of November, 2025.

/s/ CHIH-HSIANG (THOMPSON) LIN		/s/ STEFAN J. MURRY
CHIH-HSIANG (THOMPSON) LIN		STEFAN J. MURRY
President and Chief Executive Officer		Chief Financial Officer

This certification accompanies the Quarterly Report to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of Applied Optoelectronics, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Quarterly Report), irrespective of any general incorporation language contained in such filing.

Disclaimer

The opinions and information contained herein have been obtained or derived from sources believed to be reliable, but Boardroom Alpha cannot guarantee its accuracy and completeness, and that of the opinions based thereon.

This report contains opinions and is provided for informational purposes only – it does not constitute investment, legal or tax advice. You should not rely solely upon the research herein for purposes of transacting securities or other investments, and you are encouraged to conduct your own research and due diligence, and to seek the advice of a qualified securities professional before you make any investment.

None of the information contained in this report constitutes, or is intended to constitute a recommendation by Boardroom Alpha of any particular security or trading strategy or a determination by Boardroom Alpha that any security or trading strategy is suitable for any specific person. To the extent any of the information contained herein may be deemed to be investment advice, such information is impersonal and not tailored to the investment needs of any specific person.

No representation or warranty, expressed or implied, is made on behalf of Boardroom Alpha as to the accuracy or completeness of the information contained herein. Boardroom Alpha does not accept any liability for any direct, indirect or consequential loss or damage suffered by any person as a result of relying on all or any part of this research and any liability is expressly disclaimed.

Full disclaimer