Exhibit 10.28

SUPPLEMENTAL AGREEMENT

This Supplemental Agreement is made on October 31, 2009, by and among Optical
Cable Corporation, a Virginia corporation (“Buyer”), Applied Optical Systems,
Inc. (“Company”), George T. Hazelton Family Trust (“Hazelton Trust”), G. Thomas
Hazelton, Jr. (“Hazelton”), and Daniel Roehrs (“Roehrs”) and provides as
follows:

RECITALS

A. Buyer, Hazelton and Roehrs have entered into a Stock Purchase Agreement made
as of the date hereof (the “Stock Purchase Agreement”).

B. Hazelton Trust and Hazelton have each entered into separate Subordination
Agreements with the Company dated as of April 22, 2005 (collectively the
“Subordination Agreements”), regarding notes made by the Company and held
respectively by each of Hazelton Trust and Hazelton (the “Subordinated Notes”),
copies of which are attached hereto as Exhibit A attached to this Agreement.

C. The Company owes Hazelton and Roehrs those amounts set forth on Schedule
5.1(b) to the Stock Purchase Agreement for deferred salaries and deferred
commissions (the “Back Payment Amounts”).

D. Buyer has loaned funds to the Company from time to time pursuant to a Loan
and Security Agreement dated April 22, 2005, as amended from time to time prior
to or after the date of this Agreement (the “Loan Agreement”), which loan is
evidenced by a Promissory Note from the Company to the Buyer dated April 22,
2005, as amended from time to time prior to or after the date of this Agreement
(the “AOS Loan”).

E. The parties desire to make provision for payment of the Subordinated Notes
and the Back Payment Amounts, subject to the provisions of the Subordination
Agreements.

AGREEMENT

NOW, THEREFORE, in consideration of the foregoing premises, and for other good
and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto hereby agree as follows:

1. Payment of Back Payment Amounts. The Back Payment Amounts shall be paid from
positive operating cash flow of the Company (determined in accordance with
Generally Accepted Accounting Principles [“GAAP”]), generated by the Company for
periods following October 31, 2009, and such Back Payment Amounts shall be paid
by the Company once the Company (a) shall have first paid Buyer $300,000, after
the date of this Agreement, against any amounts owed Buyer by the Company, from
positive operating cash flow of the Company (determined in accordance with
GAAP), generated by the Company in periods following October 31, 2009, with any
advances made on or after the date of this Agreement to the Company by Buyer
treated as negative operating cash flow and (b) shall be current, at the time of
any such payment of Back Payment Amounts, in its accounts payable owed by the
Company to Buyer for product shipments made by Buyer to the Company on and after
the date of this Agreement. The Back Payment Amounts shall be paid to Hazelton
and Roehrs pro rata.

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2. Payment of Subordinated Notes. Subject in all respects to the provisions of
the Subordination Agreements and the Loan Agreement, and only after payment in
full of the Back Payment Amounts, the Company shall begin payment of the
Subordinated Notes at such time as any payments are made thereafter by the
Company against the AOS Loan, (with payments against the Subordinated Notes and
the AOS Loan being made pro rata based on relative account balances); provided,
however, that any such payments shall only be made from positive operating cash
flow of the Company determined in accordance with GAAP; and provided, further,
that nothing herein shall prevent payments by the Company against the AOS Loan
before payment in full of the Back Payment Amounts or from funds other than
positive operating cash flow of the Company.

3. Reaffirmation of Subordination Agreements. The parties hereto (other than
Roehrs, who is not a party to a Subordination Agreement) hereby agree that,
except as expressly provided herein, all of the terms, provisions and conditions
of their respective Subordination Agreements are hereby reaffirmed and ratified
in all respects and remain in full force and effect. In the event of any
conflict between this Agreement and any such Subordination Agreement, such
Subordination Agreement shall control.

4. Governing Law. This Agreement shall be governed by and construed, interpreted
and enforced in accordance with the laws of the Commonwealth of Virginia,
excluding its principles of conflicts of laws. Any disputes arising out of this
Agreement or any of the transactions contemplated hereby shall be adjudicated in
a State or Federal court of competent civil jurisdiction sitting in the City of
Roanoke, Virginia and nowhere else. Each of the parties hereto hereby
irrevocably submits to the jurisdiction of such court for the purposes of any
proceeding arising out of this Agreement or any of the transactions contemplated
hereby.

5. Severability. If any provision of this Agreement or the application thereof
to any person or circumstances is held invalid or unenforceable in any
jurisdiction, the remainder hereof, and the application of such provision to
such person or circumstances in any other jurisdiction, shall not be affected
thereby, and to this end the provisions of this Agreement shall be severable.

6. Absence of Third Party Beneficiary Rights. No provision of this Agreement is
intended, nor will any provision be interpreted, to provide or to create any
third party beneficiary rights or any other rights of any kind in any client,
customer, affiliate, shareholder, employee or partner of any party hereto or any
other person or entity.

7. Mutual Drafting; Person. This Agreement is the mutual product of the parties
hereto, and each provision hereof has been subject to the mutual consultation,
negotiation and agreement of each of the parties, and shall not be construed for
or against any party hereto. As used in this Agreement, the term “person” shall
mean an individual, corporation, partnership, limited liability company,
association, trust or other entity or organization, including a government or
political subdivision or an agency or instrumentality thereof.

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8. Successors and Assigns. This Agreement and the rights and obligations of the
parties hereunder may not be assigned, except (a) by operation of law and
(b) that Buyer may assign any of its rights or obligations under this Agreement
to any direct or indirect subsidiary or to any affiliate in its sole and
absolute discretion; provided, however, that Buyer shall not be released from
liability for the timely performance of Buyer’s obligations hereunder. This
Agreement shall be binding upon and shall inure to the benefit of the parties
hereto, the successors and assigns of Buyer, Hazelton Trust and the Company, and
the heirs and legal representatives of Roehrs and Hazelton.

9. Counterparts; Facsimile Transmission. This Agreement may be executed in any
number of counterparts and any party hereto may execute any such counterpart,
each of which when executed and delivered shall be deemed to be an original, and
all of which counterparts taken together shall constitute but one and the same
instrument. Any signatures delivered by a party by facsimile transmission shall
be deemed an original signature hereto.

[Execution Page Following]

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IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
day and year first above written.

 

OPTICAL CABLE CORPORATION By:  

/S/ NEIL D. WILKIN, JR.

  Name:  Neil D. Wilkin, Jr.   Title:    Chairman, President and CEO APPLIED
OPTICAL SYSTEMS, INC. By:  

/S/ G. THOMAS HAZELTON, JR.

  Name:  G. Thomas Hazelton, Jr.   Title:    General Manager

/S/ G. THOMAS HAZELTON, JR.

G. Thomas Hazelton, Jr.

/S/ DANIEL ROEHRS

Daniel Roehrs G. Thomas Hazelton Family Trust By:  

/S/ G. THOMAS HAZELTON, JR.

  Name:  G. Thomas Hazelton, Jr.   Title:    Trustee