<PAGE>


AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 10, 2004

                                                    REGISTRATION NO. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               EMCORE CORPORATION
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

             NEW JERSEY                                22-2746503
  -------------------------------         ------------------------------------
  (STATE OR OTHER JURISDICTION OF         (I.R.S. EMPLOYER IDENTIFICATION NO.)
   INCORPORATION OR ORGANIZATION)

                  145 BELMONT DRIVE, SOMERSET, NEW JERSEY 08873
                  ---------------------------------------------
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

                               EMCORE CORPORATION
                             2000 STOCK OPTION PLAN
                  ---------------------------------------------
                            (FULL TITLE OF THE PLAN)

                                THOMAS G. WERTHAN
                               EMCORE CORPORATION
                                145 BELMONT DRIVE
                           SOMERSET, NEW JERSEY 08873
                  ---------------------------------------------
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (732) 271-9090
          -------------------------------------------------------------
          (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
==============================================================================================================
       TITLE OF SECURITIES             AMOUNT TO BE     PROPOSED MAXIMUM   PROPOSED MAXIMUM     AMOUNT OF
         TO BE REGISTERED            REGISTERED(1)(2)    OFFERING PRICE   AGGREGATE OFFERING  REGISTRATION FEE
                                                           PER SHARE           PRICE
--------------------------------------------------------------------------------------------------------------
<S>                                      <C>                  <C>            <C>                  <C>
 Common Stock, without par value         2,100,000            $2.56(3)       $ 5,607,000          $ 681.14
--------------------------------------------------------------------------------------------------------------
</TABLE>

(1)  Plus an indeterminate number of additional shares of Common Stock that may
     be offered and issued pursuant to stock dividends, stock splits, or similar
     transactions.

(2)  This registration statement is being filed for purposes of registering
     2,100,000 additional shares of Common Stock of EMCORE Corporation, issuable
     pursuant to our 2000 Stock Option Plan, as amended and restated (the
     "Plan"). We have previously registered 4,750,000 shares pursuant to a
     registration statement on Form S-8 (File No. 333-60816) under the Plan. The
     registration fee for the previously registered shares was paid at the time
     that the previous registration statement was filed.

(3)  Estimated pursuant to Rule 457(h) of the General Rules and Regulations
     under the Securities Act of 1933, as amended (the "Securities Act"), for
     the purpose of computing the registration fee, based on the average of the
     high and low sales price on the NASDAQ National Market on August 4, 2004.

<PAGE>

EXPLANATORY NOTE

     Pursuant to General Instruction E of Form S-8, the registrant, EMCORE
Corporation (the "Registrant"), is filing this registration statement
("Registration Statement") with respect to the issuance of an additional
2,100,000 shares of its common stock, no par value per share (the "Common
Stock"), under the Plan.

     On May 11, 2001, the Registrant filed a registration statement (the "Prior
Registration Statement") on Form S-8 (File No. 333-60816) with respect to the
issuance of 4,750,000 shares of Common Stock under the Plan. The contents of the
Prior Registration Statement are hereby incorporated in this Registration
Statement by reference.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

     The documents containing the information specified in Part I will be sent
or given to persons to whom the information is required to be given as specified
by Rule 428(b)(1) of the Securities Act. Such documents are not being filed with
the Securities and Exchange Commission (the "Commission") either as part of this
Registration Statement or as prospectuses or prospectus supplements pursuant to
Rule 424 of the Securities Act. Such documents and the documents incorporated by
reference in this Registration Statement pursuant to Item 3 of Part II of this
Form, taken together, constitute a prospectus that meets the requirements of
Section 10(a) of the Securities Act.

                                     PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following documents filed by the Registrant with the Commission are
incorporated herein by reference:

          (1)  The Registrant's Annual Report on Form 10-K for the fiscal year
               ended September 30, 2003.

          (2)  The Registrant's Quarterly Report on Form 10-Q for the quarter
               ended December 31, 2003.

          (3)  The Registrant's Quarterly Report on Form 10-Q for the quarter
               ended March 31, 2004.

          (4)  The Registrant's Current Reports on Form 8-K filed with the
               Commission on October 14, 2003, November 18, 2003, December 29,
               2003, January 21, 2004 (2), February 17, 2004, February 19, 2004,
               and July 16, 2004, and the Registrant's


                                      -2-
<PAGE>

               Current Reports on Form 8-K/A filed with the Commission on
               February 18, 2004 and May 19, 2004.

          (5)  The Registrant's Registration Statement on Form 8-A, filed with
               the Commission on February 26, 1997 (File Number 0-22175)
               pursuant to Section 12(g) of the Securities Exchange Act of 1934,
               as amended (the "Exchange Act"), which incorporates by reference
               the description of the shares of Common Stock contained in the
               Registration Statement on Form S-1 (File Number 333-18565) filed
               by the Registrant on December 23, 1996, as amended by Amendment
               No. 1 filed on February 6, 1997, Amendment No. 2 filed on
               February 11, 1997 and Amendment No. 3 filed on February 24, 1997,
               and declared effective by the Commission on March 6, 1997, and
               any amendment or report filed with the Commission for purposes of
               updating such description.

     All reports and other documents filed by the Registrant with the Commission
pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act after the
date of this Registration Statement and prior to the filing of a post-effective
amendment to this Registration Statement, which indicates that all securities
offered hereby have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be part
hereof from the respective dates of filing of such reports and documents.


                                   SIGNATURES

     Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Somerset, State of New Jersey, on this 10th day of
August, 2004.

                    EMCORE Corporation


                    By: /s/  Thomas G. Werthan
                        ------------------------------------
                        Thomas G. Werthan
                        Chief Financial Officer


                                      -3-
<PAGE>

                                POWER OF ATTORNEY

     Each person whose signature appears below constitutes and appoints and
hereby authorizes Reuben F. Richards, Jr. and Thomas G. Werthan, severally, such
person's true and lawful attorneys-in-fact, with full power of substitution or
resubstitution, for such person and in his name, place and stead, in any and all
capacities, to sign on such person's behalf, individually and in each capacity
stated below, any and all amendments, including post-effective amendments to
this Registration Statement and to sign any and all additional registration
statements relating to the same offering of securities as this Registration
Statement that are filed pursuant to Rule 462(b) of the Securities Act, and to
file the same, with all exhibits thereto, and other documents in connection
therewith, with the Commission granting unto said attorneys-in-fact, full power
and authority to do and perform each and every act and thing requisite or
necessary to be done in and about the premises, as fully to all intents and
purposes as such person might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact, or their substitute or substitutes,
may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act, this Registration
Statement on Form S-8 has been signed by the following persons in the capacities
and on the date indicated.

<TABLE>
<CAPTION>
           SIGNATURE                           TITLE                           DATE
           ---------                           -----                           ----
<S>                                   <C>                                 <C>
                                      Chairman of the Board               August 10, 2004
---------------------------------     of Directors
       Thomas J. Russell

                                      President, Chief Executive          August 10, 2004
---------------------------------     Officer and Director
    Reuben F. Richards, Jr.           (Principal Executive Officer)

                                      Chief Financial Officer and         August 10, 2004
---------------------------------     Director (Principal Accounting
       Thomas G. Werthan              and Financial Officer)

                                      Chief Technology Officer            August 10, 2004
---------------------------------     and Director
        Richard A. Stall

                                      Director                            August 10, 2004
---------------------------------
        Robert Bogomolny

                                      Director                            August 10, 2004
---------------------------------
         John M. Gillen

                                      Director                            August 10, 2004
---------------------------------
      Robert Louis-Dreyfus

                                      Director                            August 10, 2004
---------------------------------
      Charles Thomas Scott
</TABLE>



                                      -4-
<PAGE>

                                  EXHIBIT INDEX

     Exhibit
      Number      Description
      ------      -----------

        4.1       The Registrant's 2000 Stock Option Plan, as amended and
                  restated, effective February 20, 2004.*

        4.2       Restated Certificate of Incorporation, dated December 21, 2000
                  (incorporated by reference to Exhibit 3.1 of the Registrant's
                  Annual Report on Form 10-K for the fiscal year ended
                  September 30, 2000).

        4.3       Amended By-Laws, as amended through December 21, 2000
                  (incorporated by reference to Exhibit 3.2 of the Registrant's
                  Annual Report on Form 10-K for the fiscal year ended
                  September 30, 2000).

        5.1       Opinion of Dillon, Bitar & Luther L.L.C.*

       23.1       Consent of Dillon, Bitar & Luther L.L.C. (included in
                  Exhibit 5.1 to this Registration Statement).*

       23.2       Consent of Deloitte & Touche LLP.*

       24.1       Power of Attorney (included on signature page).*


       *    Filed herewith.


                                      -5-
[{"type": "S-8", "sequence": "1", "filename": "file001.txt", "description": "FORM S-8", "secsgml_size_bytes": 12967}]
{"company-data": {"conformed-name": "EMCORE CORP", "cik": "0000808326", "assigned-sic": "3559", "irs-number": "222746503", "state-of-incorporation": "NJ", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-118076", "film-number": "04963639"}, "business-address": {"street1": "145 BELMONT DRIVE", "city": "SOMERSET", "state": "NJ", "zip": "08873", "phone": "7322719090"}, "mail-address": {"street1": "145 BELMONT DRIVE", "city": "SOMERSET", "state": "NJ", "zip": "08873"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 10, 2004

                                                    REGISTRATION NO. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                               EMCORE CORPORATION
             ------------------------------------------------------
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

             NEW JERSEY                                22-2746503
  -------------------------------         ------------------------------------
  (STATE OR OTHER JURISDICTION OF         (I.R.S. EMPLOYER IDENTIFICATION NO.)
   INCORPORATION OR ORGANIZATION)

                  145 BELMONT DRIVE, SOMERSET, NEW JERSEY 08873
                  ---------------------------------------------
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

                               EMCORE CORPORATION
                             2000 STOCK OPTION PLAN
                  ---------------------------------------------
                            (FULL TITLE OF THE PLAN)

                                THOMAS G. WERTHAN
                               EMCORE CORPORATION
                                145 BELMONT DRIVE
                           SOMERSET, NEW JERSEY 08873
                  ---------------------------------------------
                     (NAME AND ADDRESS OF AGENT FOR SERVICE)

                                 (732) 271-9090
          -------------------------------------------------------------
          (TELEPHONE NUMBER, INCLUDING AREA CODE, OF AGENT FOR SERVICE)

                         CALCULATION OF REGISTRATION FEE
==============================================================================================================
       TITLE OF SECURITIES             AMOUNT TO BE     PROPOSED MAXIMUM   PROPOSED MAXIMUM     AMOUNT OF
         TO BE REGISTERED            REGISTERED(1)(2)    OFFERING PRICE   AGGREGATE OFFERING  REGISTRATION FEE
                                                           PER SHARE           PRICE
--------------------------------------------------------------------------------------------------------------
Common Stock, without par value         2,100,000            $2.56(3)       $ 5,607,000          $ 681.14
--------------------------------------------------------------------------------------------------------------
(1)  Plus an indeterminate number of additional shares of Common Stock that may
     be offered and issued pursuant to stock dividends, stock splits, or similar
     transactions.

(2)  This registration statement is being filed for purposes of registering
     2,100,000 additional shares of Common Stock of EMCORE Corporation, issuable
     pursuant to our 2000 Stock Option Plan, as amended and restated (the
     "Plan"). We have previously registered 4,750,000 shares pursuant to a
     registration statement on Form S-8 (File No. 333-60816) under the Plan. The
     registration fee for the previously registered shares was paid at the time
     that the previous registration statement was filed.

(3)  Estimated pursuant to Rule 457(h) of the General Rules and Regulations
     under the Securities Act of 1933, as amended (the "Securities Act"), for
     the purpose of computing the registration fee, based on the average of the
     high and low sales price on the NASDAQ National Market on August 4, 2004.
EXPLANATORY NOTE

     Pursuant to General Instruction E of Form S-8, the registrant, EMCORE
Corporation (the "Registrant"), is filing this registration statement
("Registration Statement") with respect to the issuance of an additional
2,100,000 shares of its common stock, no par value per share (the "Common
Stock"), under the Plan.

     On May 11, 2001, the Registrant filed a registration statement (the "Prior
Registration Statement") on Form S-8 (File No. 333-60816) with respect to the
issuance of 4,750,000 shares of Common Stock under the Plan. The contents of the
Prior Registration Statement are hereby incorporated in this Registration
Statement by reference.

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

     The documents containing the information specified in Part I will be sent
or given to persons to whom the information is required to be given as specified
by Rule 428(b)(1) of the Securities Act. Such documents are not being filed with
the Securities and Exchange Commission (the "Commission") either as part of this
Registration Statement or as prospectuses or prospectus supplements pursuant to
Rule 424 of the Securities Act. Such documents and the documents incorporated by
reference in this Registration Statement pursuant to Item 3 of Part II of this
Form, taken together, constitute a prospectus that meets the requirements of
Section 10(a) of the Securities Act.

                                     PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

     The following documents filed by the Registrant with the Commission are
incorporated herein by reference:

          (1)  The Registrant's Annual Report on Form 10-K for the fiscal year
               ended September 30, 2003.

          (2)  The Registrant's Quarterly Report on Form 10-Q for the quarter
               ended December 31, 2003.

          (3)  The Registrant's Quarterly Report on Form 10-Q for the quarter
               ended March 31, 2004.

          (4)  The Registrant's Current Reports on Form 8-K filed with the
               Commission on October 14, 2003, November 18, 2003, December 29,
               2003, January 21, 2004 (2), February 17, 2004, February 19, 2004,
               and July 16, 2004, and the Registrant's

                                      -2-
Current Reports on Form 8-K/A filed with the Commission on
               February 18, 2004 and May 19, 2004.

          (5)  The Registrant's Registration Statement on Form 8-A, filed with
               the Commission on February 26, 1997 (File Number 0-22175)
               pursuant to Section 12(g) of the Securities Exchange Act of 1934,
               as amended (the "Exchange Act"), which incorporates by reference
               the description of the shares of Common Stock contained in the
               Registration Statement on Form S-1 (File Number 333-18565) filed
               by the Registrant on December 23, 1996, as amended by Amendment
               No. 1 filed on February 6, 1997, Amendment No. 2 filed on
               February 11, 1997 and Amendment No. 3 filed on February 24, 1997,
               and declared effective by the Commission on March 6, 1997, and
               any amendment or report filed with the Commission for purposes of
               updating such description.

     All reports and other documents filed by the Registrant with the Commission
pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act after the
date of this Registration Statement and prior to the filing of a post-effective
amendment to this Registration Statement, which indicates that all securities
offered hereby have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference herein and to be part
hereof from the respective dates of filing of such reports and documents.

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Somerset, State of New Jersey, on this 10th day of
August, 2004.

                    EMCORE Corporation

                    By: /s/  Thomas G. Werthan
                        ------------------------------------
                        Thomas G. Werthan
                        Chief Financial Officer

                                      -3-
POWER OF ATTORNEY

     Each person whose signature appears below constitutes and appoints and
hereby authorizes Reuben F. Richards, Jr. and Thomas G. Werthan, severally, such
person's true and lawful attorneys-in-fact, with full power of substitution or
resubstitution, for such person and in his name, place and stead, in any and all
capacities, to sign on such person's behalf, individually and in each capacity
stated below, any and all amendments, including post-effective amendments to
this Registration Statement and to sign any and all additional registration
statements relating to the same offering of securities as this Registration
Statement that are filed pursuant to Rule 462(b) of the Securities Act, and to
file the same, with all exhibits thereto, and other documents in connection
therewith, with the Commission granting unto said attorneys-in-fact, full power
and authority to do and perform each and every act and thing requisite or
necessary to be done in and about the premises, as fully to all intents and
purposes as such person might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact, or their substitute or substitutes,
may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act, this Registration
Statement on Form S-8 has been signed by the following persons in the capacities
and on the date indicated.
SIGNATURE                           TITLE                           DATE
           ---------                           -----                           ----
Chairman of the Board               August 10, 2004
---------------------------------     of Directors
       Thomas J. Russell

                                      President, Chief Executive          August 10, 2004
---------------------------------     Officer and Director
    Reuben F. Richards, Jr.           (Principal Executive Officer)

                                      Chief Financial Officer and         August 10, 2004
---------------------------------     Director (Principal Accounting
       Thomas G. Werthan              and Financial Officer)

                                      Chief Technology Officer            August 10, 2004
---------------------------------     and Director
        Richard A. Stall

                                      Director                            August 10, 2004
---------------------------------
        Robert Bogomolny

                                      Director                            August 10, 2004
---------------------------------
         John M. Gillen

                                      Director                            August 10, 2004
---------------------------------
      Robert Louis-Dreyfus

                                      Director                            August 10, 2004
---------------------------------
      Charles Thomas Scott
-4-
EXHIBIT INDEX

     Exhibit
      Number      Description
      ------      -----------

        4.1       The Registrant's 2000 Stock Option Plan, as amended and
                  restated, effective February 20, 2004.*

        4.2       Restated Certificate of Incorporation, dated December 21, 2000
                  (incorporated by reference to Exhibit 3.1 of the Registrant's
                  Annual Report on Form 10-K for the fiscal year ended
                  September 30, 2000).

        4.3       Amended By-Laws, as amended through December 21, 2000
                  (incorporated by reference to Exhibit 3.2 of the Registrant's
                  Annual Report on Form 10-K for the fiscal year ended
                  September 30, 2000).

        5.1       Opinion of Dillon, Bitar & Luther L.L.C.*

       23.1       Consent of Dillon, Bitar & Luther L.L.C. (included in
                  Exhibit 5.1 to this Registration Statement).*

       23.2       Consent of Deloitte & Touche LLP.*

       24.1       Power of Attorney (included on signature page).*

       *    Filed herewith.

                                      -5-