THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED
UNDER THE SECURITIES ACT OF 1933, AND HAVE BEEN ACQUIRED FOR INVESTMENT AND NOT
WITH A VIEW TO, OR IN CONNECTION WITH, THE SALE OR DISTRIBUTION THEREOF.  NO
SUCH SALE OR DISTRIBUTION MAY BE EFFECTED WITHOUT AN EFFECTIVE REGISTRATION
STATEMENT RELATED THERETO OR AN OPINION OF COUNSEL IN A FORM SATISFACTORY TO
THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES ACT OF
1933.

                            SECURED PROMISSORY NOTE


$450,000.00                                                      March 28, 2003
                                                            Clearwater, Florida

      For  value received, Digital Lightwave, Inc., a Delaware corporation (the
"Company"),  promises to pay to Optel, LLC (the "Holder"), the principal sum of
Four Hundred Fifty  Thousand Dollars ($450,000.00).  Interest shall accrue from
the date of this Note  on  the unpaid principal amount at a rate equal to 10.0%
per annum, compounded annually. This Note is subject to the following terms and
conditions.

      1.    MATURITY.  Principal and any accrued but unpaid interest under this
Note shall be due and payable  upon demand by the Holder at any time after July
31, 2004 (the "Maturity Date").   Notwithstanding  the  foregoing,  the  entire
unpaid  principal  sum  of this Note, together with accrued and unpaid interest
thereon, shall become immediately  due  and  payable  immediately  prior to the
earlier  to  occur  of  (a)  a  Change  of Control (as defined below), (b)  the
insolvency of the Company, (c) the commission  of  any act of bankruptcy by the
Company,  (d)  the  execution by the Company of a general  assignment  for  the
benefit of creditors, (e) the filing by or against the Company of a petition in
bankruptcy or any petition  for  relief under the federal bankruptcy act or the
continuation of such petition without  dismissal  for  a  period  of 90 days or
more, or (f) the appointment of a receiver or trustee to take possession of the
property  or  assets  of  the Company.  For purposes of this Note a "Change  of
Control" shall mean a sale of all or substantially all of the Company's assets,
or any merger or consolidation of the Company with or into another corporation;
other than a merger or consolidation  in  which the holders of more than 50% of
the shares of capital stock of the Company  outstanding  immediately  prior  to
such  transaction  continue  to hold (either by the voting securities remaining
outstanding or by their being converted into voting securities of the surviving
entity) more than 50% of the total  voting  power  represented  by  the  voting
securities  of  the  Company, or such surviving entity, outstanding immediately
after such transaction.

      2.    PAYMENT; PREPAYMENT.  All payments shall be made in lawful money of
the United States of America  at  such place as the Holder hereof may from time
to time designate in writing to the  Company.   Payment shall be credited first
to  the  accrued interest then due and payable and  the  remainder  applied  to
principal. Prepayment of this Note may be made at any time without penalty.

      3.    TRANSFER; SUCCESSORS AND ASSIGNS.  The terms and conditions of this
Note shall  inure  to  the  benefit  of  and  be  binding  upon  the respective
successors and assigns of the parties.   This Note may be transferred only upon
surrender of the original Note for registration of transfer, duly  endorsed, or
accompanied  by  a  duly  executed  written  instrument  of  transfer  in  form
satisfactory  to  the  Company.   Thereupon,  a new note for the same principal
amount  and interest will be issued to, and registered  in  the  name  of,  the
transferee.   Interest  and principal are payable only to the registered holder
of this Note.

      4.    GOVERNING LAW.   This  Note  and all acts and transactions pursuant
hereto and the rights and obligations of the  parties hereto shall be governed,
construed and interpreted in accordance with the  laws of the State of Florida,
without giving effect to principles of conflicts of law.

      5.    NOTICES.  Any notice required or permitted  by this Agreement shall
be  in  writing  and  shall be deemed sufficient upon receipt,  when  delivered
personally or by courier, overnight delivery service or confirmed facsimile, or
48 hours after being deposited in the U.S. mail as certified or registered mail
with postage prepaid, if  such  notice is addressed to the party to be notified
at  such  party's  address  or facsimile  number  as  set  forth  below  or  as
subsequently modified by written notice.

      6.    AMENDMENTS AND WAIVERS.   Any term of this Note may be amended only
with the written consent of the Company  and  the  Holder.   Any  amendment  or
waiver  effected  in  accordance  with this Section 6 shall be binding upon the
Company, each Holder and each transferee of any Note.

      8.    OFFICERS AND DIRECTORS  NOT LIABLE.  In no event shall any, officer
or director of the Company be liable for any amounts due or payable pursuant to
this Note.

      9.    SECURITY INTEREST.  This  Note  is  secured by all of the assets of
the Company in accordance with a separate security  agreement  originally dated
as  of  February 14, 2003 and amended and restated as of the date  hereof  (the
"Security Agreement"), between the Company and the Holder.  In case of an Event
of Default  (as  defined  in the Security Agreement), the Holder shall have the
rights set forth in the Security Agreement.

      10.   COUNTERPARTS.    This  Note  may  be  executed  in  any  number  of
counterparts, each of which will  be  deemed to be an original and all of which
together will constitute a single agreement.

      11.   ACTION TO COLLECT ON NOTE.   If  action is instituted to collect on
this  Note,  the  Company  promises to pay all costs  and  expenses,  including
reasonable attorney's fees, incurred in connection with such action.

      12.   LOSS OF NOTE.  Upon receipt by the Company of evidence satisfactory
to it of the loss, theft, destruction  or  mutilation  of this Note or any Note
exchanged for it, and indemnity satisfactory to the Company  (in  case of loss,
theft or destruction) or surrender and cancellation of such Note (in  the  case
of  mutilation),  the  Company will make and deliver in lieu of such Note a new
Note of like tenor.



      This Note was entered into as of the date set forth above.

                                           COMPANY:

                                           DIGITAL LIGHTWAVE, INC.


                                           By:_________________________________

                                           Name:_______________________________
                                                          (print)
                                           Title:______________________________



AGREED TO AND ACCEPTED:

OPTEL, LLC


By:  ___________________________

Name: _________________________
                 (print)
Title:  __________________________






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