EXHIBIT 10.1

_____________________________________________
CONFIDENTIAL TREATMENT REQUESTED___________________________________________

CERTAIN PORTIONS INDICATED BY [*****]
HAVE BEEN OMITTED PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT. THE OMITTED NON-PUBLIC
PORTIONS HAVE BEEN FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION.

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AMENDMENT NO. 5

This AMENDMENT NO. 5
(AMENDMENT) to DEVELOPMENT AGREEMENT effective as of, as amended by AMENDMENT
NO. 1 effective as of September 6, 2001, AMENDMENT NO. 2 effective as of November 30,
2003, AMENDMENT NO. 3 effective as of July 28, 2004 and AMENDMENT NO. 4 effective as of
March 26, 2004, made by and between Canon Inc., a Japanese corporation having its
principal place of business at 30-2, Shimomaruko 3-chome, Ohta-ku, Tokyo 146-8501, Japan
(CANON) and Zygo Corporation, a Delaware corporation having its principal
place of business at 21 Laurel Brook Road, Middlefield, Connecticut 06455-0448, U.S.A.
(ZYGO), each sometimes referred to hereinafter as a PARTY and
jointly as the PARTIES to this AMENDMENT,

WITNESSETH:

WHEREAS, CANON and ZYGO entered into
the DEVELOPMENT AGREEMENT, as subsequently amended by AMENDMENT NO. 1, AMENDMENT NO. 2,
AMENDMENT NO. 3 and AMENDMENT NO. 4 thereto (the ORIGINAL AGREEMENT) under
which CANON and ZYGO have been developing a certain interferometer and figure measurement
machines; and

WHEREAS, the PARTIES have agreed to
proceed with another PROJECT (as defined in the ORIGINAL AGREEMENT) under the terms and
conditions thereof;

NOW, THEREFORE, the PARTIES hereby
agree as follows:

1.    
          EXHIBIT A-3 attached hereto shall be added to EXHIBIT A of the ORIGINAL
          AGREEMENT and become part thereof.

2.    
          Except as expressly provided herein, all of the terms and conditions of the
          ORIGINAL AGREEMENT shall continue in effect.

3.    
          This AMENDMENT shall become effective as of November 28, 2003, irrespective of
          the date signed below.

IN WITNESS WHEREOF, the PARTIES have
caused this AMENDMENT to be executed in duplicate originals by their duly authorized
representatives as of the date last signed below.

|                                                                      |  |                                                   
|--------------------------------------------------------------------- |  | --------------------------------------------------
|CANON INC.                                                            |  | ZYGO CORPORATION                                  
|BY:                /s/ Hironori Yamamoto
Hironori Yamamoto            |  | BY:              /s/ Bruce Robinson
Bruce Robinson
|Group Executive, Managing Director                    Core Technology |  |                                                   
|TITLE:     Development Headquarters                                   |  | TITLE:     President                              
|DATE:     February 23, 2005                                           |  | DATE:     February 26, 2005                       

1

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EXHIBIT A-3

PROJECT 3. (Additional development for M#1)

1.  TARGET PRODUCT

| | The
following components and tools for the TARGET PRODUCT specified in EXHIBIT A-1 (the
figure measurement machine identified as Machine 1) of which fundamental
specifications and requirements are separately agreed upon by the PARTIES; and which
fully meet the FINAL SPECIFICATIONS
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (1)  [*****] lens and [*****] lens
| | ----------------------------------

| | (2)  [*****] lens and [*****] lens
| | ----------------------------------

| | (3)  [*****] lens and [*****] lens
| | ----------------------------------

| | (4)  [*****] Tools-N1
| | ---------------------

| | (5)  [*****] Tools-N2
| | ---------------------

| | (6)  [*****] Tools-N3
| | ---------------------

| | (The M1 [*****] Tool-[*****] is a mechanism used during calibration of the reference surface
in the M#1 figure measurement machine [*****].)
| | --------------------------------------------------------------------------------------------------------------------------------------------

| | (7)  [*****]#1
| | --------------

| | (8)  [*****]#2
| | --------------

| | (9)  [*****]#3
| | --------------

| | ([*****].)
| | ----------

| | (10)  MFI1.5
| | ------------

| | (MFI1.5
is an interferometry unit to be used as part of the M#1 figure measurement machine.  The
MFI1.5 is a [*****].)
| | ----------------------------------------------------------------------------------------------------------------------

2.  Scope of the PROJECT

| | Design,
development (development includes manufacturing one (1) unit of each of the
TARGET PRODUCT that materialize the result thereof) of the TARGET PRODUCT, including
associated tools and accessories (such as software, tools, and electronics) and
installment of each such one (1) unit of the TARGET PRODUCT (including associated tools
and accessories) at CANONs premise.
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(Works to be performed by CANON)

|(1) | Delivery
of the DRAFT SPECIFICATIONS to be determined by CANON
|--- | --------------------------------------------------------------

|(2)                 | (For [*****] lenses and [*****] lenses)    | Mechanical
      design and manufacturing
|------------------- | ------------------------------------------ | -----------------------------------------
|(For [*****] Tools) | Manufacture
      of optical units thereof

|(3) | Acceptance
test of TARGET PRODUCT as installed at CANONs facility
|--- | ------------------------------------------------------------------

(Works to be performed by ZYGO)

|(1) | Creation
and delivery of the proposed FINAL SPECIFICATIONS of the TARGET PRODUCT
|--- | --------------------------------------------------------------------------------

|(2) | (For
      [*****] lenses and [*****] lenses) | Optical
      design                                                                                                 
|--- | --------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------
|    | (For
      [*****] Tools)                     | Design,
      manufacturing of mechanical unit and assembling the mechanical unit and
      the optical unit         
|    | (For
      [*****])                           | Design
      and manufacturing                                                                                       
|    | (For
      MFI1.5)                            | Design
      and manufacturing (by incorporating [*****] lens and [*****] lens therefore
      manufactured by CANON)

|(3) | Creation of documentation for testing, use and maintenance of the TARGET PRODUCT
|--- | --------------------------------------------------------------------------------

| | Details
of the PROJECT other than those specified herein shall be separately agreed upon by the
PARTIES.
| | --------------------------------------------------------------------------------------------------------

2

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3. DELIVERABLES

(From CANON to ZYGO)

|(1) | DRAFT
SPECIFICATIONS
|--- | --------------------

|(2) | Optical units of [*****] Tools
|--- | ------------------------------

(From ZYGO to CANON)

|(1) | Proposed FINAL SPECIFICATIONS
|--- | -----------------------------

|(2) | One (1) unit of respective TARGET PRODUCT
|--- | -----------------------------------------

|(3) | Reports of evaluation (including the final inspection report) by ZYGO of each TARGET PRODUCT
|--- | --------------------------------------------------------------------------------------------

|(4) | Documentation for testing, use and maintenance
|--- | ----------------------------------------------

Details
of the DELIVERABLES other than those specified herein shall be separately agreed upon by
the PARTIES.

4. Development Schedule

|(1) | [*****] lens and [*****] lens | (Delivered
      as of the execution date)
|--- | ----------------------------- | ------------------------------------------

|(2) | [*****] lens and [*****] lens | (Delivered
      as of the execution date)
|--- | ----------------------------- | ------------------------------------------

|(3) | [*****] lens and [*****] lens | (Delivered
      as of the execution date)
|--- | ----------------------------- | ------------------------------------------

|(4) | [*****] Tools-N1 | (To
      be delivered by February 28, 2005)
|--- | ---------------- | --------------------------------------------

|(5) | [*****] Tools-N2 | (To
      be delivered by March 28, 2005)
|--- | ---------------- | -----------------------------------------

|(6) | [*****] Tools-N3 | (To
      be delivered by April 28, 2005)
|--- | ---------------- | -----------------------------------------

|(7) | [*****]#1 | (Delivered
      as of the execution date)
|--- | --------- | ------------------------------------------

|(8) | [*****]#2 | (To
      be delivered by April 4, 2005)
|--- | --------- | ----------------------------------------

|(9) | [*****]#3 | (To
      be delivered by May 2, 2005)
|--- | --------- | --------------------------------------

|(10) | M#1.5 | (To
      be delivered by May 15, 2005)
|---- | ----- | ---------------------------------------

Completion of the PROJECT   (Target Date)              May 15,
2005

5.  Development
Fee

| | In
full and complete consideration for this PROJECT performed by ZYGO hereunder, including
without limitation, the costs of the DELIVERABLES of ZYGO, CANON agrees to pay to ZYGO
Two Million Three Hundred Twelve Thousand Eight Hundred Forty-Eight US Dollars
(US$2,312,848) in accordance with the following payment schedule subject to issuance of
invoice therefor by ZYGO prior to each payment due date:
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (1) | One
Hundred Ten Thousand  Thirty-Two US Dollars  (US$110,032)  within sixty (60) days of
CANON's  receipt of a fully                   executed original of the AMENDMENT;
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (2) | Forty-Three
 Thousand Fifty-Six US Dollars (US$43,056) within sixty (60) days of CANON's receipt of a
fully executed                   original of the AMENDMENT;
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (3) | Seventy-One
 Thousand  Seven Hundred  Sixty US Dollars  (US$71,760)  within sixty (60) days of
CANON's  receipt of a                   fully executed original of the AMENDMENT;
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (4) | Sixty-Three
 Thousand US Dollars  (US$63,000)  within sixty (60) days of CANON's  receipt of both
Nshear Tools-N1 of                   the TARGET PRODUCT and the final inspection report
thereof by ZYGO;
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (5) | Fifty-Five
 Thousand US Dollars (US$55,000) within sixty (60) days of CANON's receipt of both Nshear
Tools-N2 of the                   TARGET PRODUCT and the final inspection report thereof
by ZYGO;
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (6) | Fifty-five
 Thousand US Dollars (US$55,000) within sixty (60) days of CANON's receipt of both Nshear
Tools-N3 of the                   TARGET PRODUCT and the final inspection report thereof
by ZYGO;
| | --- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (7) | One
Hundred and Five Thousand US Dollars  (US$105,000) within sixty (60) days of CANON's
receipt of a fully executed                   original of the AMENDMENT;
| | --- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (8) | Two
Hundred and Five  Thousand US Dollars  (US$205,000)  within sixty (60) days of CANON's
 receipt of both TSM#2 of                   the TARGET PRODUCT and the final inspection
report thereof by ZYGO;
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (9) | Two
Hundred and Five  Thousand US Dollars  (US$205,000)  within sixty (60) days of CANON's
 receipt of both TSM#3 of                   the TARGET PRODUCT and the final inspection
report thereof by ZYGO; and
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (10) | One
Million Four Hundred Thousand US Dollars  (US$1,400,000)  within sixty (60) days of
CANON's receipt of MFI1.5 of                   the TARGET PRODUCT which was inspected by
ZYGO and CANON at ZYGO's premise before delivery.
| | ---- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

3