Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No. )

Your Vote Counts! *Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V91944-P50354 APPLIED OPTOELECTRONICS, INC. ATTN: LEGAL DEPARTMENT 13139 JESS PIRTLE BLVD. SUGAR LAND, TX 77478 APPLIED OPTOELECTRONICS, INC. Notice of 2026 Annual Meeting Vote by June 3, 2026 11:59 PM ET You invested in APPLIED OPTOELECTRONICS, INC. and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the stockholder meeting to be held on June 4, 2026. Get informed before you vote View the Notice and Proxy Statement and Annual Report online OR you can receive a free paper or email copy of the material(s) by requesting prior to May 21, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. 13139 Jess Pirtle Blvd. Sugar Land, TX 77478 Vote in Person at the Meeting* June 4, 2026 9:30 A.M. Central Time

Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. V91945-P50354 Voting Items Board Recommends THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. Class I Directors for Election: For Nominees: 01) Che-Wei Lin 02) Robert (Bob) Flanagan 2. To ratify the appointment of Grant Thornton LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2026. For 3. To approve, on an advisory basis, the compensation of our named executive officers. For 4. To approve the amendment of our Amended and Restated Certificate of Incorporation, as amended, to clarify the voting standard that applies to certain future amendments. For 5. To approve the 2026 equity incentive plan. For 6. To approve an adjournment of the Annual Meeting to a later date or dates, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, one or more of the other proposals to be voted on at the Annual Meeting. For NOTE: In their discretion, the Proxies (or their substitutes) are authorized to vote upon such other business as may properly come before the meeting or any adjournment or postponement of the meeting including, without limitation, procedural and other matters related to the conduct of the meeting (such as adjournment to a later time or place) and the election of a substitute or alternate nominee if any nominee named above is unwilling or unable to, or for good cause will not, serve if elected.

	¨	Preliminary Proxy Statement
	¨	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
	¨	Definitive Proxy Statement
	x	Definitive Additional Materials
	¨	Soliciting Material under §240.14a-12

	x	No fee required.
	¨	Fee paid previously with preliminary materials.
	¨	Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11