<PAGE>



                                 Attachment A-1
            SPECTRAN CORPORATION FIRST AMENDMENT TO TRUST INDENTURE

                                                                  Exhibit 10.118

                                 FIRST AMENDMENT

         FIRST AMENDMENT (this  "Amendment")  dated as of September 30, 1998, by
and among SPECTRAN CORPORATION (the "Company"), a Delaware corporation, SPECTRAN
COMMUNICATION  FIBER  TECHNOLOGIES,   INC.  ("SCFT"),  a  Delaware  corporation,
SPECTRAN SPECIALTY OPTICS COMPANY ("SSOC"), a Delaware corporation,  and APPLIED
PHOTONIC DEVICES,  Inc.  ("APD"),  a Delaware  corporation  (SCFT, SSOC and APD,
together with their respective successors and assigns, referred to individually,
as a "Guarantor,"  and,  collectively,  as the "Guarantors;" the Company and the
Guarantors being referred to herein as the  "Obligors"),  Fleet National Bank, a
national banking  association (the "Former Trustee") as security trustee under a
certain Trust  Indenture (as amended and as may be further  amended from time to
time, the "Trust  Indenture"),  dated as of December 1, 1996 among the Obligors,
the Former  Trustee and the other  parties  thereto,  and STATE  STREET BANK AND
TRUST COMPANY, a Massachusetts trust company, as successor to the Former Trustee
and in its  capacity as  security  trustee,  together  with its  successors  and
assigns and any co-trustees  that becomes such in accordance with the provisions
of the Trust Indenture, the "Trustee").

1.       Preliminary Statement

         (a) The Obligors entered into a certain  Trademark  Security  Agreement
(the "Existing Trademark Security Agreement"),  dated as of December 1, 1996, in
favor of the Former Trustee to secure the  obligations of the Obligors  pursuant
to the Lending Documents.  The Existing Trademark Security Agreement, as amended
by this  Amendment,  is referred to herein as the  "Amended  Trademark  Security
Agreement."

<PAGE>

         (b) All acts and proceedings  required by law and by the certificate or
articles  of  incorporation  and  bylaws of each of the  Obligors  necessary  to
constitute  this  Amendment  a valid  and  binding  agreement  for the  uses and
purposes set forth  herein,  in  accordance  with its terms,  have been done and
taken,  and the  execution  and delivery  hereof has been in all  respects  duly
authorized.

2.       Defined Terms

         The terms used  herein  have the  meanings  specified  in the  Existing
Trademark Security Agreement unless otherwise defined herein.

3.       Amendments to Terms of Existing Trademark Security Agreement

         The Existing Trademark Security Agreement is amended as follows:

         (a)      in connection  with the resignation of Fleet National Bank, as
                  Trustee,  as  acknowledged  by  Fleet  National  Bank  by  its
                  execution and delivery of this Amendment,  and the appointment
                  of State Street Bank and Trust Company as successor trustee as
                  acknowledged  by State Street Bank and Trust  Company and each
                  of the Obligors by their respective  execution and delivery of
                  this  Amendment,  all references to Fleet National Bank in its
                  capacity as Trustee  are hereby  amended to be  references  to
                  State Street Bank and Trust Company as Trustee; and

         (b)      Exhibit 1 thereto is amended and restated in its entirety as
                  set forth on Exhibit 1 hereto.


<PAGE>



                                                         
      SPECTRAN CORPORATION FIRST AMENDMENT TO TRADEMARK SECURITY AGREEMENT

15.      REPRESENTATIONS, WARRANTIES AND COVENANTS OF OBLIGORS

         Each  of the  representations,  warranties  and  covenants  made by the
Obligors  in  respect  of the  Trademarks  set forth in the  Existing  Trademark
Security  Agreement are incorporated  herein by reference and are made as of the
date hereof and  immediately  after the  effectiveness  hereof and after  giving
effect hereto, there exists no Default or Event of Default.

4.       Scope and Effect of Amendment

         Except as expressly  provided  herein,  no terms or  provisions  of the
Existing Trademark Security Agreement are modified or changed by this Amendment,
and the  terms and  provisions  of the  Existing  Trademark  Security  Agreement
continue in full force and effect.

         Each of the  Obligors  hereby  acknowledges,  confirms,  reaffirms  and
ratifies all of its obligations  and duties under the Lending  Documents and all
agreements  related thereto.  This Amendment does not constitute an agreement or
obligation of any Beneficiary to give its consent to any future amendment of any
Lending Document or to any future transaction that would,  absent consent of the
Beneficiaries, constitute a Default or Event of Default under any of the Lending
Documents.  This Amendment may not be  contradicted by evidence of any actual or
alleged prior, contemporaneous or subsequent understandings or agreements of the
parties,  written  or oral,  express  or  implied,  other  than a writing  which
expressly amends or supersedes this Amendment or the Lending Documents. Upon the
effectiveness  of this Amendment,  each reference in any Lending Document to any
Trademark  Security  Agreement  shall mean and be a reference  to the  Trademark
Security Agreement as amended hereby.

<PAGE>

5.       Miscellaneous

         (a) Successors and Assigns

         This  Amendment  shall bind and inure to the benefit of the  respective
successors and assigns of the Obligors, the Trustee and the Beneficiaries.

(1)      Expenses

         The Company will pay, or cause to be paid, the reasonable out-of-pocket
costs and  expenses  of each  Beneficiary  and the  Trustee in  connection  with
entering  into  this  Amendment  and  the   consummation  of  all   transactions
contemplated  hereby.  The  obligations  of the Company  under this Section 6(b)
shall survive payment of any Secured Obligations.

(2)      Effectiveness

         This Amendment may be executed in one or more counterparts and shall be
effective,  as of the date hereof, when at least one counterpart shall have been
executed by each of the parties hereto.

      [Remainder of page intentionally blank. Next page is signature page.]


<PAGE>



     SPECTRAN  CORPORATION  FIRST AMENDMENT TO TRADEMARK  SECURITY  AGREEMENT IN
WITNESS WHEREOF, the parties hereto have caused this Amendment to be executed on
their behalf by a duly authorized officer or agent thereof,  as the case may be,
as of the date first above written.

Signed, sealed and delivered                       SPECTRAN CORPORATION
in the presence of:


                                                    By: ------------------------

                                                    Name:
                                                    Title:


                                                    SPECTRAN COMMUNICATION FIBER
                                                              TECHNOLOGIES, INC.


                                                    By: ------------------------

                                                    Name:
                                                    Title:


                                                   SPECTRAN SPECIALTY OPTICS
                                                              COMPANY


                                                    By: ------------------------

                                                    Name:
                                                    Title:



                                                  APPLIED PHOTONIC DEVICES, INC.


                                                     By: -----------------------

                                                     Name:
                                                     Title:






<PAGE>


                                          FLEET NATIONAL BANK, as Former Trustee



                                                     By: -----------------------

                                                     Name:
                                                     Title:




<PAGE>



                                 STATE STREET BANK AND TRUST COMPANY, as Trustee


                                                   By: -------------------------

                                                   Name:
                                                   Title:



<PAGE>


STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument as the  _________________________ of SPECTRAN CORPORATION, a Delaware
corporation, and acknowledged that such corporation executed the same.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]




STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument  as the  _________________________  of SPECTRAN  COMMUNICATION  FIBER
TECHNOLOGIES,   INC.,  a  Delaware  corporation,   and  acknowledged  that  such
corporation executed the same.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]



<PAGE>


STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument  as  the   _________________________  of  SPECTRAN  SPECIALTY  OPTICS
COMPANY, a Delaware corporation, and acknowledged that such corporation executed
the same.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]



STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument as the _________________________ of APPLIED PHOTONIC DEVICES, INC., a
Delaware corporation, and acknowledged that such corporation executed the same.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]




<PAGE>


STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument as the  _________________________  of FLEET NATIONAL BANK, a national
banking  association,  and acknowledged  that such national banking  association
executed the same as security trustee thereunder.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]



<PAGE>




STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument  as the  _________________________  of STATE  STREET  BANK AND  TRUST
COMPANY, a Massachusetts trust company, and acknowledged that such Massachusetts
trust company executed the same as security trustee thereunder.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]


<PAGE>



                                  Exhibit 1 - 2
      SPECTRAN CORPORATION FIRST AMENDMENT TO TRADEMARK SECURITY AGREEMENT
                                                                      EXHIBIT 1

                              TRADEMARK ASSIGNMENT


         WHEREAS, [NAME OF OBLIGOR], a [________]  corporation,  (the "Obligor")
owns and has used in its business certain trademarks which are registered or for
which a registration has been applied for, as listed in Schedule A hereto; and

         WHEREAS,  an "Event of  Default"  has  occurred  under the terms of the
Trust  Indenture,  dated as of December 1, 1996, as amended,  among the Obligor,
certain of its  affiliates,  and State  Street  Bank and Trust  Company,  in its
capacity  as  security  trustee  (the  "Trustee")  and  the  Trademark  Security
Agreement,  dated as of December 1, 1996, as amended, among the Obligor, certain
of its affiliates and the Trustee (collectively, the "Security Documents"); and

         WHEREAS,  the Trustee,  pursuant to its rights as a secured party under
the  Security  Documents,  and  pursuant  to and in  exercise of its rights as a
secured party under the  Massachusetts  Uniform  Commercial  Code, has chosen to
exercise its rights upon default;

         NOW  THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency of which are hereby acknowledged,  and intending to be legally bound
hereby,  the Obligor does hereby  absolutely sell,  assign,  transfer and convey
unto the Trustee all of the Obligor's right, title and interest in and to:

                  (i) the trademarks, together with the goodwill of the business
         symbolized  by  the  trademarks,  the  registrations  and  applications
         thereof as set forth on Schedule A attached hereto;

                  (ii) all trade names, trade styles,  service marks, prints and
         labels on which said trademarks,  trade names, trade styles and service
         marks have appeared or appear,  designs and general intangibles of like
         nature; and

                  (iii)  all  proceeds  of  the  foregoing  (including,  without
         limitation, license royalties and proceeds of infringement suits).

         IN  WITNESS  WHEREOF,  [NAME OF  OBLIGOR]  has  caused  this  Trademark
Assignment to be duly executed by its duly authorized officer as of ____________
___, 199__.

                                    [NAME OF OBLIGOR]


                                    By:____________________________
                                            Name:
                                            Title:


<PAGE>



STATE OF _______________                    )
                                                     )  ss.
COUNTY OF _____________                     )

         On _______________,  before me, the undersigned, a notary public in and
for said County and State,  duly  commissioned  and sworn,  personally  appeared
_____________________________,  personally  known to me or proved to me to be on
the basis of  satisfactory  evidence  to be the person who  executed  the within
instrument       as       the       ___________________________________       of
_________________________,  a _______________ corporation, and acknowledged that
such corporation executed the same.

         IN WITNESS WHEREOF, I have hereunto set my hand and affixed my official
seal the day and year in this certificate first above written.


                                                 Notary Public in and for the
                                                 County of ____________________,
                                                 State of ______________________
                                       My Commission Expires: __________________
                                                              [SEAL]


<PAGE>



                                  Schedule A-1
      SPECTRAN CORPORATION FIRST AMENDMENT TO TRADEMARK SECURITY AGREEMENT
                                                                    Schedule A


             TRADEMARKS AND TRADEMARK APPLICATIONS AND REGISTRATIONS