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                              SPECTRAN CORPORATION

                                                                  EXHIBIT 10.106

THE SHARES  REPRESENTED BY THIS  CERTIFICATE  ARE RESTRICTED BY AND SUBJECT TO A
CONVERSION AGREEMENT AMONG SPECTRAN  CORPORATION,  ALLEN & COMPANY INCORPORATED,
RICHARD A.M.C.  JOHNSON AND PATRICK E. BRAKE DATED AS OF NOVEMBER 8, 1990 AND ON
FILE AT THE OFFICES OF THE COMPANY.

Void after August 14, 1999      Right to Purchase 150,000 Shares of Common Stock
                                 (subject to adjustment) of SpecTran Corporation

     SPECTRAN CORPORATION

     COMMON STOCK PURCHASE WARRANT

SPECTRAN CORPORATION (the "Company"),  a Delaware corporation,  hereby certifies
that, for value received, ALLEN & COMPANY INCORPORATED, or assigns, is entitled,
subject to the terms set forth below,  to purchase  from the Company at any time
on or from time to time after  August 14,  1990 and before  5:00 P.M.,  New York
City time, on August 14, 1999, 150,000 fully paid and  non-assessable  shares of
Common Stock of the Company,  at the price per share (the  "Purchase  Price") of
$2.00.  The number and character of such shares of Common Stock and the Purchase
Price are subject to adjustment as provided herein.

     This Common Stock  Purchase  Warrant (the  "Warrant")  is issued to Allen &
Company Incorporated as of November 8, 1990 and evidencing the right to purchase
an  aggregate  of not more than  150,000  shares of Common Stock of the Company,
subject to adjustment as provided herein.  These are the remaining shares from a
Warrant to purchase  350,000  shares which was  exercised,  in part, for 200,000
shares, on February 18, 1997.  150,000 of these shares was originally subject to
a warrant  issued  August  14,  1981 and  another  100,000  of these  shares was
originally  subject to a warrant  issued  August 14, 1986;  both  warrants  were
amended and  incorporated  into this Warrant in accordance  with the  Conversion
Agreement (defined below).

     As used herein the following terms,  unless the context otherwise requires,
have the following respective meanings:

     (a)  The term "Company"  includes any corporation which shall succeed to or
          assume the obligations of the Company hereunder.

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                              SPECTRAN CORPORATION


     (b)  The term  "Common  Stock"  includes  all stock of any class or classes
          (however  designated)  of the  Company,  authorized  upon the Original
          Issue Date or  thereafter,  the holders of which shall have the right,
          without  limitation  as to amount,  either to all or to a share of the
          balance of  current  dividends  and  liquidating  dividends  after the
          payment of  dividends  and  distributions  on any shares  entitled  to
          preference,  and the holders of which shall ordinarily, in the absence
          of  contingencies,  be entitled to vote for the election of a majority
          of directors of the Company (even though the right so to vote has been
          suspended by the happening of such a contingency).

     (c)  "Conversion  Agreement"  shall  mean the  Conversion  Agreement  among
          SpecTran Corporation,  Allen & Company Incorporated ("Allen"), Richard
          A.M.C.  Johnson  ("Johnson"),  145  La  Vereda  Road,  Santa  Barbara,
          California  93108, and Patrick E. Brake  ("Brake"),  711 Fifth Avenue,
          New York, New York 10022, dated as of November 8, 1990.

     (d)  The  "Original  Issue Date" is November 8, 1990,  the date as of which
          the Warrants were first issued.

     (e)  The term  "Other  Securities"  refers to any stock  other than  Common
          Stock)  and  other  securities  of the  Company  or any  other  person
          (corporate or otherwise) which the holders of the warrants at any time
          shall be  entitled  to  receive,  or  shall  have  received,  upon the
          exercise of the  Warrants,  in lieu of or in addition to Common Stock,
          or which at any time shall be  issuable  or shall have been  issued in
          exchange for or in  replacement  of Common  Stock or Other  Securities
          pursuant to section 7 or otherwise.

     (f)  The terms  "registered"  and  "registration"  refer to a  registration
          effected by filing a  registration  statement in  compliance  with the
          Securities  Act, to permit the  disposition  of Common Stock (or Other
          Securities) issued or issuable upon the exercise of Warrants,  and any
          post-effective amendment and supplements filed or required to be filed
          to permit any such disposition.

     (g)  The term "Securities Act" means the Securities Act of 1933 as the same
          shall be in effect at the time.

     (h)  The term  "Warrants"  shall mean,  collectively,  the warrant  held by
          Allen to purchase  350,000 shares of Common Stock  (individually,  the
          "Allen  Warrant"),  the  warrant  held by Johnson to  purchase  30,000
          shares of Common Stock (individually,  the "Johnson Warrant"), and the
          warrant  held by Brake to  purchase  20,000  shares  of  Common  Stock
          (individually, the "Brake Warrant"). The term "Warrant" shall mean the
          warrant evidenced by this document.


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                              SPECTRAN CORPORATION


     1. Registration, etc.

          1.1 In the event that the  Company  proposes,  at any time  within the
four year period  commencing  one year from the Original  Issue Date,  to file a
registration  statement  (including a  registration  statement to be filed under
subparagraph 1.2 hereof) on a general form of registration  under the Securities
Act and relating to  securities  issued or to be issued by it, or if the Company
has filed such a  registration  statement and proposes to file a  post-effective
amendment  thereto within the four year period  described in the first clause of
this sentence,  then it shall give written notice of such proposal to Allen. If,
within thirty (30) days after the giving of such notice,  Allen shall request in
writing  that all or any of such  Common  Stock or Other  Securities  issued  or
issuable   upon   exercise  of  the  Warrants  be  included  in  such   proposed
registration,  the  Company  will,  at  its  own  expense,  also  register  such
securities as shall have been requested by Allen in writing; provided,  however,
that:

     (a)  the record  owners of such  securities  shall deliver to the Company a
          statement in writing  from the  beneficial  owners of such  securities
          that they bona fide intend to sell,  transfer or otherwise  dispose of
          such securities;

     (b)  the Company  shall not be  required to include any of such  securities
          if, by reason of such  inclusion,  the  Company  shall be  required to
          prepare and file a registration statement on a form promulgated by the
          Securities and Exchange  Commission  substantially  differed from that
          which the Company otherwise would use;

     (c)  such record and/or  beneficial owners shall cooperate with the Company
          in the preparation of registration statement to the extent required to
          furnish information concerning such owners therein; and

     (d)  if any  underwriter  or managing  agent is purchasing or arranging for
          the sale of the  securities  then being  offered by the Company  under
          such registration statement, then such record and/or beneficial owners
          (i) shall agree to have the securities  being so registered sold to or
          by  such   underwriter  or  managing  agent  on  terms   substantially
          equivalent to the terms at which the Company is selling the securities
          so registered, or (ii) shall delay the sale of such securities for the
          30 day period  commencing with the effective date of the  registration
          statement, provided that, if such owner elects, alternative (i) and if
          the  underwriter  or managing  agent shall in good faith object to the
          sale at that time of such securities, then the sale of such securities
          may be delayed  for a period not to exceed 90 days from the  effective
          date of such registration statement.

          1.2 After  one year from the  Original  Issue  Date,  but prior to the
expiration  of four years from the date  thereof,  the  Company  will,  upon the
written request of Allen, prepare and file as promptly as is reasonably possible
upon being furnished with the requisite information

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                              SPECTRAN CORPORATION

for such purpose, and use its reasonable best efforts to make effective,  at the
expense of the  registered  owners of  Warrants  and/or  shares of Common  Stock
issued  upon the  exercise  of the  Warrants  which are the  subject  of Allen's
request,  a registration  statement (but only two) covering such Common Stock or
Other Securities issued or issuable upon exercise of such Warrants  requested to
be sold by Allen.

          1.3 In connection with the filing of a registration statement pursuant
to subsections 1.1 or 1.2 of this section 1, the Company shall:

     (a)  notify Allen as to the filing  thereof and of all  amendments  thereto
          filed prior to the effective date of said registration statement;

     (b)  notify Allen promptly after it shall have received notice thereof,  of
          the time when the  registration  statement  becomes  effective  or any
          supplement  to  any  prospectus  forming  a part  of the  registration
          statement has been filed;

     (c)  prepare  and  file  any  necessary  amendment  or  supplement  to such
          registration  statement  or  prospectus  as may be necessary to comply
          with section 10(a)(3) of the Securities Act or advisable in connection
          with  the  proposed  distribution  of the  securities  by  the  owners
          thereof;

     (d)  use its reasonable  best efforts to qualify the shares of Common Stock
          or Other  Securities being so registered for sale under the securities
          or blue sky laws of not more than eight states as Allen may  designate
          in writing and to  register  or obtain the  approval of any federal or
          state  authority which may be required in connection with the proposed
          distribution,  except,  in each case,  in  jurisdictions  in which the
          Company must either  qualify to do business or file a general  consent
          to  service of process as a  condition  to the  qualification  of such
          securities;

     (e)  notify Allen of any stop order  suspending  the  effectiveness  of the
          registration  statement and use its reasonable  best efforts to remove
          such stop order;

     (f)  undertake to keep said registration statement and prospectus effective
          for a period of nine months  after such  shares of Common  Stock first
          become free to be sold under such registration statement;

     (g)  furnish to Allen as soon as available, copies of any such registration
          statement and each  preliminary or final prospectus and any supplement
          or  amendment  required  to be  prepared  pursuant  to  the  foregoing
          provisions  of this  paragraph 1, all in such  quantities as Allen may
          from

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                              SPECTRAN CORPORATION


          time to time  reasonably  request.  The Company shall furnish to Allen
          without cost one set of the Exhibits to such registration statement.

          1.4  The  record  owners  of the  shares  of  Common  Stock  or  Other
Securities being so registered  agree to pay all of the  underwriting  discounts
and commissions,  transfer taxes,  registration  fees and their own counsel fees
with respect to the securities owned by them and being  registered.  The Company
agrees that the costs and expenses  which it is  obligated to pay in  connection
with a registration  statement to be filed pursuant to subsection 1.1 above, and
the record owners agree that the costs and expenses  which they are obligated to
pay  in  connection  with a  registration  statement  to be  filed  pursuant  to
subsection 1.2 above,  include, but are not limited to, the fees and expenses of
counsel for the Company,  the fees and expenses of its accountants and all other
costs and expenses  incident to the  preparation,  printing and filing under the
Securities  Act of any such  registration  statement,  each  prospectus  and all
amendments and  supplements  thereto,  the costs incurred in connection with the
qualification  of such  securities  for  sale in not  more  than  eight  states,
including fees and  disbursements  of counsel for the Company,  and the costs of
supplying a  reasonable  number of copies of the  registration  statement,  each
preliminary  prospectus,  final  prospectus  and any  supplements  or amendments
thereto to Allen.

          1.5 The Company  agrees to enter into an  appropriate  cross-indemnity
agreement  with any  underwriter  (as  defined in the  Securities  Act) for such
record owners in connection with the filing of a registration statement pursuant
to subsections 1.1 or 1.2 hereof.

          1.6  In the  event  that  the  Company  shall  file  any  registration
statement  including  therein all or any part of shares of Common Stock or Other
Securities  issued or issuable upon  exercise of the  Warrants,  the Company and
each  record  and/or  beneficial  owner of such  securities  shall enter into an
appropriate  cross-indemnity  agreement  whereby each such owner shall indemnify
and hold harmless the Company,  each of its directors,  each of its officers who
have signed the registration statement and each person, if any, who controls the
Company  within the meaning of the  Securities  Act against any losses,  claims,
damages or liabilities (or actions in respect  thereof)  arising out of or based
upon any untrue  statement or alleged  untrue  statement  of any  material  fact
contained in such registration statement, or any omission or alleged omission to
state therein a material fact required to be stated therein or necessary to make
the statements therein not misleading,  if the statement or omission was made in
reliance upon and in conformity with written  information  furnished or required
to be furnished by such owner or such  controlling  person  expressly for use in
such registration statement.

     2. Sale or Exercise Without Registration.  If, at the time of any exercise,
transfer or  surrender  for  exchange of a Warrant or of Common  Stock (or Other
Securities)  previously  issued upon the exercise of  Warrants,  such Warrant or
Common Stock (or Other  Securities) shall not be registered under the Securities
Act, the Company may require, as a condition or allowing such exercise, transfer
or exchange,  that the owner or  transferee  of such Warrant or Common Stock (or
Other  Securities),  as the case may be,  furnish to the Company a  satisfactory
opinion of counsel to the effect that such exercise, transfer or exchange may be
made  without   registration   under  the  Securities  Act,  provided  that  the
disposition  thereof  shall at all times be within the

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                              SPECTRAN CORPORATION


control of such owner or  transferee,  as the case may be, and provided  further
that  nothing  contained  in this  section  2 shall  relieve  the  Company  from
complying with any request for registration  pursuant to section 1 hereof. Allen
or its assigns,  Johnson or his assigns,  and Brake or his assigns,  as the case
may be, in each case as the first holder of his or its Warrant represents to the
Company that he or it is  acquiring  the Warrant for  investment  and not with a
view to the distribution thereof.

     3. Right of First  Refusal.  The Allen  Warrant and Common  Stock (or Other
Securities)  previously  issued upon the exercise of the Allen  Warrant shall be
subject to the right of first refusal and other procedures  contained in Section
3. of the Conversion Agreement.

     4. Exercise of Warrant; Partial Exercise.

          4.1 Exercise in Full. Subject to the provisions  hereof,  this Warrant
may be exercised in full by the holder thereof by surrender of the Warrant, with
the form of subscription at the end hereof duly executed by such holder,  to the
Company at its principal office in Sturbridge, Mass., accompanied by payment, in
cash or by certified or official bank check payable to the order of the Company,
in the amount  obtained  by  multiplying  the  number of shares of Common  Stock
called for on the face of the Warrant  (without  giving effect to any adjustment
therein) by the Purchase Price.

          4.2 Partial Exercise.  Subject to the provisions hereof,  this Warrant
may be  exercised  in part by  surrender of the Warrant in the manner and at the
place  provided in subsection  4.1 except that the amount  payable by the holder
upon any partial  exercise shall be the amount  obtained by multiplying  (a) the
number of  shares  of Common  Stock  (without  giving  effect to any  adjustment
therein)  designated by the holder in the  subscription at the end hereof by (b)
the Purchase Price. Upon any such partial  exercise,  the Company at its expense
will  forthwith  issue and deliver to or upon the order of the holder  thereof a
new warrant or warrants of like tenor,  in the name of the holder  thereof or as
such holder (upon payment by such holder of any applicable  transfer  taxes) may
request, calling in the aggregate on the face or faces thereof for the number of
shares of Common Stock equal (without  giving effect to any adjustment  therein)
to the number of such shares called for on the face of the  partially  exercised
warrant  minus  the  number  of such  shares  designated  by the  holder  in the
subscription at the end hereof.

          4.3 Company to Reaffirm Obligations.  The Company will, at the time of
any  exercise  of  this  Warrant,  upon  the  request  of  the  holder  thereof,
acknowledge  in writing its  continuing  obligation to afford to such holder any
rights (including,  without limitation,  any right to registration of the shares
of Common  Stock or Other  Securities  issued upon such  exercise) to which such
holder shall continue to be entitled after such exercise in accordance  with the
provisions  of this  Warrant,  provided that if the holder of this Warrant shall
fail to make any such  request,  such  failure  shall not affect the  continuing
obligation of the Company to afford such holder any such rights.

     5.  Delivery  of  Stock  Certificates,   etc.,  on  Exercise.  As  soon  as
practicable  after the exercise of this  Warrant in full or in part,  and in any
event  within 10 days  thereafter,  the

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                              SPECTRAN CORPORATION


Company at its  expense  (including  the payment by it of any  applicable  issue
taxes)  will  cause to be  issued  in the name of and  delivered  to the  holder
hereof,  or as such  holder  (upon  payment  by such  holder  of any  applicable
transfer  taxes) may direct,  a certificate  or  certificates  for the number of
fully paid and  non-assessable  shares of Common Stock (or Other  Securities) to
which such holder shall be entitled  upon such  exercise,  plus,  in lieu of any
fractional share to which such holder would otherwise be entitled, cash equal to
such  fraction  multiplied  by the then current  market value of one full share,
together with any other stock or other securities and property  (including cash,
where  applicable) to which such holder is entitled upon such exercise  pursuant
to section 6 or otherwise.

     6.   Adjustment   for   Dividends   in   Other   Stock,   Property,   etc.;
Reclassification,  etc.In  case  at any  time or from  time  to time  after  the
Original Issue Date the holders of Common Stock (or Other Securities) shall have
received,  or (on or after  the  record  date  fixed  for the  determination  of
stockholders eligible to receive) shall have become entitled to receive, without
payment therefor

     (a)  other or additional  stock or other securities or property (other than
          cash) by way of dividend, or

     (b)  any cash paid or payable  (including,  without  limitation,  by way of
          dividend), except out of earned surplus of the Company, or

     (c)  other or  additional  (or less) stock or other  securities or property
          (including  cash)  by way  of  spin-off,  split-up,  reclassification,
          recapitalization,   combination   of  shares  or   similar   corporate
          rearrangement,

then, and in each such case the holder of this Warrant, upon the exercise hereof
as  provided  in section 4, shall be entitled to receive the amount of stock and
other  securities  and  property  (including  cash in the  case  referred  to in
subdivisions  (b) and (c) of this section 6) which such holder would hold on the
date of such  exercise if on the  Original  Issue Date it had been the holder of
record of the  number of shares of Common  Stock  called for on the face of this
Warrant and had  thereafter,  during the period from the Original  Issue Date to
and including the date of such exercise, retained such shares and all such other
or additional (or less) stock and other securities and property  (including cash
in the  cases  referred  to in  subdivisions  (b)  and (c) of  this  section  6)
receivable  by  it as  aforesaid  during  such  period,  giving  effect  to  all
adjustments called for during such period by section 7 and 8 hereof.

     7. Reorganization, Consolidation, Merger, etc.

          7.1 General.  In case the Company after the Original  Issue Date shall
(a)  effect a  reorganization,  (b)  consolidate  with or merge  into any  other
person,  or (c) transfer all or substantially all of its properties or assets to
any other person under any plan or arrangement  contemplating the dissolution of
the Company within 24 months from the date of such transfer,  then, in each such
case,  the holder of this  Warrant,  upon the  exercise  hereof as  provided  in
section 4 at any time after the  consummation of such  dissolution,  as the case
may be,  shall be  entitled  to receive  (and the  Company  shall be entitled to
deliver),  in lieu of the Common Stock

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                              SPECTRAN CORPORATION


(or Other Securities)  issuable upon such exercise prior to such consummation or
such  effective  date, the stock and other  securities  and property  (including
cash) to which such holder would have been entitled upon such consummation or in
connection  with such  dissolution,  as the case may be, if such  holder  had so
exercised  this  Warrant  immediately  prior  thereto,  all  subject  to further
adjustment thereafter as provided in section 6 and 8 hereof.

     The Company agrees that in the event that it effects a  consolidation  with
or merger into any other person,  it shall be a condition of such  consolidation
or merger that the resulting entity agree to register all shares or other shares
or  other  securities  under  the  Securities  Act of 1933 so that  all  persons
receiving  shares  in the  consolidation  or  merger  shall be free to sell said
shares pursuant to an effective  registration  statement  immediately  after the
consolidation or merger.

          7.2  Warrant  to   Continue  in  Full  Force  and  Effect.   Upon  any
reorganization, consolidation, merger or transfer (and any dissolution following
any transfer)  pursuant to section 7.1 this Warrant shall continue in full force
and effect and the terms hereof shall be  applicable  to the shares of stock and
other securities and property receivable upon the exercise of this Warrant after
the  consummation of such  reorganization,  consolidation,  merger,  transfer or
dissolution,  as the case may be,  and shall be  binding  upon the issuer of any
such stock or other securities, including, in the case of any such transfer, the
person  acquiring all or  substantially  all of the  properties or assets of the
Company,  whether or not such person shall have  expressly  assumed the terms of
this Warrant.

     8. Other Adjustments.

          8.1  General.  In any case to which  sections  6 and 8 hereof  are not
applicable,  where the Company  shall  issue or sell shares of its Common  Stock
after the Original  Issue Date,  other than shares  issued or sold in connection
with options or rights granted pursuant to the Company's  Incentive Stock Option
Plan  (or any  similar  plan it might  adopt),  without  consideration  or for a
consideration  per share less than the Purchase Price in effect  pursuant to the
terms of this Warrant at the time of issuance or sale of such additional shares,
except  where such  shares are issued or sold  pursuant  to the  exercise of any
warrant or option or issued prior to the date of this Warrant, then the Purchase
Price in effect  hereunder  shall  simultaneously  with such issuance or sale be
reduced to a price  determined  by dividing (1) an amount equal to (a) the total
number of shares of Common Stock outstanding  immediately prior to such issuance
or sale multiplied by the Purchase Price in effect hereunder at the time of such
issuance or sale, plus (b) the  consideration,  if any,  received by the Company
upon such  issuance  or sale by (2) the total  number of shares of Common  Stock
outstanding immediately after issuance or sale of such additional shares.

          8.2  Convertible  Securities.  In case the Company shall issue or sell
any  securities  convertible  into  Common  Stock of the  Company  ("Convertible
Securities")  after  the  date  hereof,  other  than  shares  issued  or sold in
connection  with options or rights granted  pursuant to the Company's  Incentive
Stock  Option  Plan  (or any  similar  plan it  might  adopt),  there  shall  be
determined  the price per share for  which  Common  Stock is  issuable  upon the
conversion or exchange  thereof,  such  determination to be made by dividing (a)
the total amount

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                              SPECTRAN CORPORATION


received or receivable by the Company as  consideration,  if any, payable to the
Company upon the  conversion or exchange  thereof,  by (b) the maximum number of
shares of Common Stock of the Company  issuable upon the  conversion or exchange
of all of such Convertible Securities.

     If the  price  per share so  determined  shall be less than the  applicable
Purchase Price per share, then such issue or sale shall be deemed to be an issue
or sale  for  cash  (as of the  date  of  issue  or  sale  of  such  Convertible
Securities)  of such  maximum  number of shares of Common Stock at the price per
share so determined,  provided  that, if such  Convertible  Securities  shall by
their terms provide for an increase or  increases,  with the passage of time, in
the amount of additional  consideration,  if any, to the Company, or in the rate
of exchange,  upon the  conversion or exchange  thereof,  the adjusted  purchase
price per share shall,  forthwith upon any such increase becoming effective,  be
readjusted to reflect the same, and provided  further,  that upon the expiration
of such rights of conversion or exchange of such Convertible Securities,  if any
thereof shall not have been  exercised,  the adjusted  Purchase  Price per share
shall  forthwith be readjusted  and  thereafter be the price which it would have
been had an  adjustment  been made on the basis  that the only  shares of Common
Stock so issued or sold were issued or sold upon the  conversion  or exchange of
such  Convertible  securities,  and  that  they  were  issued  or  sold  for the
consideration actually received by the Company upon such conversion or exchange,
plus the  consideration,  if any, actually received by the Company for the issue
or sale of all of such Convertible Securities which shall have been converted or
exchanged.

          8.3 Rights and Options.  In case the Company shall grant any rights or
options,  other  than  options  or  rights  granted  pursuant  to the  Company's
Incentive  Stock Option Plan (or any similar plan it might adopt),  to subscribe
for, purchase or otherwise  acquire Common Stock,  there shall be determined the
price per share for which  Common  Stock is issuable  upon the  exercise of such
rights or  options,  such  determination  to be made by  dividing  (a) the total
amount,  if any,  received or receivable by the Company as consideration for the
granting  of such  rights  or  options,  plus the  minimum  aggregate  amount of
additional consideration payable to the Company upon the exercise of such rights
or options,  by (b) the maximum  number of shares of Common Stock of the Company
issuable upon the exercise of such rights or options.

     If the  price  per share so  determined  shall be less than the  applicable
Purchase  Price per share,  then the granting of such rights or options shall be
deemed to be an issue or sale for cash (as of the date of the  granting  of such
rights or options) of such maximum number of shares of Common Stock at the price
per share so determined, provided that, if such rights or options shall by their
terms  provide for an increase or  increases,  with the passage of time,  in the
amount of  additional  consideration  payable to the Company  upon the  exercise
thereof,  the adjusted  purchase price per share shall,  forthwith upon any such
increase  becoming  effective,  be readjusted to reflect the same, and provided,
further,  that upon the  expiration  of such rights or  options,  if any thereof
shall not have been  exercised,  the  adjusted  Purchase  Price per share  shall
forthwith be readjusted and thereafter be the price which it would have been had
an  adjustment  been made on the basis that the only  shares of Common  Stock so
issued or sold were those  issued or sold upon the  exercise  of such  rights or
options  and  that  they  were  issued  or sold for the  consideration

<PAGE>   10

                              SPECTRAN CORPORATION


actually received by the Company upon such exercise, plus the consideration,  if
any,  actually  received by the  Company  for the  granting of all such right or
options, whether or not exercised.

     9.  Further  Assurances.  The  Company  will take all such action as may be
necessary or appropriate in order that the Company may validly and legally issue
fully paid and non-assessable  shares of stock upon the exercise of all Warrants
from time to time outstanding.

     10.  Accountant's  Certificate  as to  Adjustments.  In  each  case  of any
adjustment or readjustment  in the shares of Common Stock (or Other  Securities)
issuable  upon the  exercise of the  Warrants,  the Company at its expense  will
promptly  cause  the  Company's  regularly  retained  auditor  to  compute  such
adjustment  or  readjustment  in  accordance  with the terms of the Warrants and
prepare a certificate  setting forth such adjustment or readjustment and showing
in detail the facts upon which such adjustment or readjustment is based, and the
number of shares of Common Stock  outstanding or deemed to be  outstanding.  The
Company will forthwith mail a copy of each such  certificate to each holder of a
Warrant.

     11. Notices of Record Date, etc. In the event of

     (a)  any taking by the  Company of a record of the  holders of any class of
          securities for the purpose of determining  the holders thereof who are
          entitled to receive any dividend  (other than a cash dividend  payable
          out of earned  surplus of the Company) or other  distribution,  or any
          right to subscribe  for,  purchase or otherwise  acquire any shares of
          stock of any class or any other securities or property,  or to receive
          any other right, or

     (b)  any capital  reorganization of the Company,  any  reclassification  or
          recapitalization  of the capital  stock of the Company or any transfer
          of  all  or  substantially  all  the  assets  of  the  Company  to  or
          consolidation  or merger of the Company with or into any other person,
          or

     (c)  any voluntary or involuntary dissolution, liquidation or winding-up of
          the Company, or

     (d)  any  proposed  issue or grant by the Company of any shares of stock of
          any class or any other securities, or any right or option to subscribe
          for, purchase or otherwise acquire any shares of stock of any class or
          any other securities  (other than (i) in connection with the Company's
          Incentive  Stock Option Plan (or any similar plan it might adopt),  or
          (ii) the issue of Common Stock on the exercise of the Warrants),  then
          and in each such event the Company  will mail or cause to be mailed to
          each holder of a Warrant a notice specifying (i) the date on which any
          such  record  is to  be  taken  for  the  purpose  of  such  dividend,
          distribution  or right,  and stating the amount and  character of such
          dividend,  distribution  or  right,  (ii) the  date on which  any such
          reorganization,    reclassification,    recapitalization,    transfer,
          consolidation,  merger,  dissolution,  liquidation or winding-up is to
          take

<PAGE>   11

                              SPECTRAN CORPORATION


          place,  and the  time,  if any,  as of which  the  holder of record of
          Common Stock (or Other Securities) shall be entitled to exchange their
          shares of Common Stock (or Other  Securities)  for securities or other
          property  deliverable  upon  such  reorganization,   reclassification,
          recapitalization,   transfer,   consolidation,   merger,  dissolution,
          liquidation or  winding-up,  and (iii) the amount and character of any
          stock or other securities,  or rights or options with respect thereto,
          proposed to be issued or granted,  the date of such proposed  issue or
          grant and the persons or class of persons to whom such proposed  issue
          or grant is to be  offered  or made.  Such  notice  shall be mailed at
          least 20 days prior to the date therein specified.

     12.  Reservation  of Stock,  etc.  Issuable on Exercise  of  Warrants.  The
Company will at all times  reserve and keep  available,  solely for issuance and
delivery upon the exercise of the Warrants, all shares of Common Stock (or Other
Securities) from time to time issuable upon the exercise of the Warrants.

     13. Listing on Securities  Exchanges;  Registration.  If the Company at any
time shall list any Common Stock on any national  securities  exchange and shall
register such Common Stock under the Securities Exchange Act of 1934 (as then in
effect, or any similar statue then in effect), the Company will, at its expense,
simultaneously list on such exchange,  upon official notice of issuance upon the
exercise of the  Warrants,  and  maintain  such  listing of all shares of Common
Stock from time to time  issuable  upon the  exercise of the  Warrants;  and the
Company will so list on any national securities  exchange,  will so register and
will  maintain  such  listing  of all  shares of Common  Stock from time to time
issuable upon the exercise of the Warrants;  and the Company will so list on any
national  securities  exchange,  will so register and will maintain such listing
of, any Other Securities if and at the time that any securities of like class or
similar  type  shall be  listed  on such  national  securities  exchange  by the
Company.

     14. Exchange of Warrants.  Subject to the provisions of paragraph 2 hereof,
upon surrender for exchange of any Warrant,  properly endorsed,  to the Company,
the  Company at its own  expense  will issue and deliver to or upon the order of
the holder thereof a new warrant or warrants of like tenor,  in the name of such
holder or as such holder (upon payment by such holder of any applicable transfer
taxes) may direct, calling in the aggregate on the face or faces thereof for the
number of shares of common  Stock called for on the face or faces of the warrant
or warrants so surrendered.

     15.   Replacement  of  Warrants.   Upon  receipt  of  evidence   reasonably
satisfactory to the Company of the loss, theft, destruction of mutilation of any
Warrant and, in the case of any such loss,  theft or destruction,  upon delivery
of an  indemnity  agreement  reasonably  satisfactory  in form and amount to the
Company or, in the case of any such mutilation,  upon surrender and cancellation
of such  Warrant,  the Company at its expense will execute and deliver,  in lieu
thereof, a new warrant of like tenor.


<PAGE>   12

                              SPECTRAN CORPORATION


     16. Warrant  Agent.  The Company may, by written notice to each holder of a
Warrant,  appoint  an agent  having an office  in New  York,  New York,  for the
purpose of issuing Common Stock (or Other  Securities)  upon the exercise of the
Warrants pursuant to section 4, exchanging  Warrants pursuant to section 14, and
replacing  Warrants  pursuant  to  section  15,  or any of  the  foregoing,  and
thereafter any such issuance, exchange or replacement, as the case may be, shall
be made at such office by such agent.

     17. Remedies. The Company stipulates that the remedies at law of the holder
of this Warrant in the event of any default or threatened default by the Company
in the  performance  of or compliance  with any of the terms of this Warrant are
not and will not be adequate,  and that such terms may be specifically  enforced
by a decree for the specific performance of any agreement contained herein or by
an injunction against a violation of any of the terms hereof or otherwise.

     18. Negotiability, etc. This Warrant is issued upon the following terms, to
all of which each  holder or owner  hereof by the  taking  hereof  consents  and
agrees:

     (a)  subject  to the  provisions  hereof,  title  to  this  Warrant  may be
          transferred by endorsement (by the holder hereof executing the form of
          assignment  at the end hereof)  and  delivery in the same manner as in
          the case of a negotiable  instrument  transferable  by endorsement and
          delivery;

     (b)  subject to the  foregoing,  any person in  possession  of this Warrant
          properly endorsed is authorized to represent himself as absolute owner
          hereof  and  is  empowered  to  transfer   absolute  title  hereto  by
          endorsement  and delivery  hereof to a bona fide purchaser  hereof for
          value;  each  prior  taker or owner  waives and  renounces  all of his
          equities  or  rights in this  Warrant  in favor of each such bona fide
          purchaser and each such bona fide  purchaser  shall  acquire  absolute
          title hereto and to all rights represented hereby; and

     (c)  until this Warrant is  transferred  on the books of the  Company,  the
          Company may treat the  registered  holder hereof as the absolute owner
          hereof for all purposes, notwithstanding any notice to the contrary.

     19. Notices,  etc. All notices and other communications from the Company to
the  holder  of this  Warrant  shall be  mailed  by first  class  registered  or
certified mail, postage prepaid, at such addresses as may have been furnished to
the Company in writing by such holder, or, until and address is so furnished, to
and at the address of the last holder of this  Warrant who has so  furnished  an
address to the Company.

     20. Miscellaneous. This Warrant and any term hereof may be changed, waived,
discharged  or terminated  only by an instrument in writing  signed by the party
against which  enforcement of such change,  waiver,  discharge or termination is
sought.  This  Warrant is being  delivered in the State of New York and shall be
construed  and  enforced  in  accordance  with

<PAGE>   13

                              SPECTRAN CORPORATION


and  governed by the laws of such State.  The  headings in this  Warrant are for
purposes of reference  only, and shall not limit or otherwise  affect any of the
terms hereof.

     21. Extended Expiration. The right to exercise this Warrant shall expire at
5:00 P.M., New York City time, on August 14, 1999,  provided,  however,  that if
the holders of Warrants  issued  hereunder  have, in  accordance  with the terms
hereof, requested a registration statement pursuant to subsection 1.2 hereof and
such  registration  statement has not become  effective  prior to the expiration
date of the right to exercise  this  Warrant,  then the right to  exercise  this
Warrant shall be extended and shall expire 30 days after the  effective  date of
such registration statement.

     22. Assignability. This Warrant is fully assignable at any time.

Dated:

                                                   SPECTRAN CORPORATION

                                                   By__________________________

[Corporate Seal]

Attest:

___________________________
        Secretary


<PAGE>   14

                              SPECTRAN CORPORATION


FORM OF SUBSCRIPTION

                  (To be signed only upon exercise of Warrant)

To:  SPECTRAN CORPORATION

     The  undersigned,  the holder of the  within  Warrant,  hereby  irrevocably
elects to exercise the purchase  right  represented  by such Warrant for, and to
purchase   thereunder,     *    shares  of  Voting   Common  Stock  of  SpecTran
Corporation,  and herewith  makes  payment of $ thereof,  and requests  that the
certificates  for such  shares  be  issued  in the name of,  and  delivered  to,
                  , whose address is

Dated:

                              _________________________________________________
                             (Signature must conform in all respects to name of
                                holder as specified on the face of the Warrant)

                              _________________________________________________
                                                    (Address)

--------
     *   Insert here the number of shares  called for on the face of the Warrant
         (or, in the case of a partial exercise, the portion thereof as to which
         the  Warrant is being  exercised),  in either case  without  making any
         adjustment  for  additional  Common  Stock or any other  stock or other
         securities  or  property  or cash  which,  pursuant  to the  adjustment
         provisions of the Warrant, may be deliverable upon exercise.

<PAGE>   15

                              SPECTRAN CORPORATION


                               FORM OF ASSIGNMENT

                  (To be signed only upon transfer of Warrant)

          For  value  received,   the  undersigned  hereby  sells,  assigns  and
transfers unto the right represented by the within warrant to purchase ** shares
of Voting Common Stock of SpecTran Corporation which the within warrant relates,
and  appoints  Attorney  to  transfer  such  right  on  the  books  of  SpecTran
Corporation  with full power of substitution in the premises.  The warrant being
transferred  hereby is one of an  aggregate  of 350,000  Common  Stock  Purchase
warrants  issued by SpecTran  Corporation to Allen & Company  Incorporated as of
November 8, 1990.

Dated:

                              _________________________________________________
                             (Signature must conform in all respects to name of
                                holder as specified on the face of the Warrant)

                              _________________________________________________
                                                    (Address)


--------
     **  Signature  guaranteed by a Bank or Trust  Company  having its principal
         office in New York City or by a Member Firm of the New York or American
         Stock Exchange.