JENNER&BLOCK

January 21, 2004                    Jenner & Block LLP           Chicago
                                    601 Thirteenth Street, NW    Dallas
                                    Suite 1200 South             Washington, DC
                                    Washington, DC 20005-3823
                                    Tel  202 639-6000
                                    www.jenner.com


EMCORE Corporation
145 Belmont Drive
Somerset, NJ 08873






Re:      Registration of Securities on Form S-4

Ladies and Gentlemen:

         We are acting as special counsel to EMCORE Corporation, a New Jersey
corporation (the "Company"), in connection with the registration by the Company
of $88,962,500 aggregate principal amount of the Company's 5% Convertible Senior
Subordinated Notes due 2011 (the "Notes") and shares of common stock of the
Company, no par value per share issuable upon conversion of the notes (the
"Conversion Shares"), and, if the Company exercised its right to provisionally
redeem the Notes, at its option, in payment of the early call premium (the
"Provisional Redemption Shares"), and that will be issued in combination with
the Notes in exchange for the Company's 5% Convertible Subordinated Notes due
2006 (the "Exchange Shares" and, collectively with the Conversion Shares and the
Provisional Redemption Shares, the "Shares"), pursuant to a Registration
Statement on Form S-4 (Registration No. 333-111585) filed with the Securities
and Exchange Commission (the "Commission") on December 24, 2004 under the
Securities Act of 1933, as amended (the "Securities Act") (such Registration
Statement, as amended or supplemented, the "Registration Statement").

         The Notes are to be issued pursuant to an Indenture (the "Indenture"),
the form of which has been filed as Exhibit 4.3 to the Registration Statement,
to be entered into between the Company and Deutsche Bank Trust Company Americas,
as trustee.

         We have examined originals, or copies certified or otherwise identified
to our satisfaction, of such documents, corporate records and other instruments
as we have deemed necessary for the purposes of this opinion, including (a) the
corporate and organizational documents of the Company, (b) certain minutes and
records of the corporate proceedings of the Company, (c) the Indenture, (d) a
specimen of the Notes, (e) a specimen certificate representing the Shares and
(f) the Registration Statement and exhibits thereto.

         For purposes of this opinion, we have assumed the authenticity of all
documents submitted to us as originals, the conformity to the originals of all
documents submitted to us as copies and the authenticity of the originals of all
documents submitted to us as copies. We have also assumed the genuineness of the
signatures of persons signing all documents in connection with which this
opinion is rendered, the authority of such persons signing on behalf of the
parties thereto other than the Company, and the due authorization, execution and
delivery of all documents by the parties thereto other than the Company. As to
any facts material to the opinions expressed herein which we have not
independently established or verified, we have


EMCORE
January 21, 2004
Page 2

relied upon statements and representations of officers and other representatives
of the Company and others. We have also made other assumptions which we believe
to be appropriate for purposes of this letter.

         Based upon and subject to the qualifications, assumptions and
limitations set forth in this letter, we are of the opinion that:

         1. When, as and if (a) the Registration Statement shall have become
effective pursuant to the provisions of the Securities Act, (b) the Indenture
shall have been duly authorized, executed and delivered by the Company and the
Trustee, (c) the Notes shall have been duly issued in the form and containing
the terms described and provided in the Prospectus, the Indenture and the
respective Company corporate proceedings, and any legally required consents,
approvals, authorizations and other orders of the Commission and any other
regulatory authorities with respect thereto shall have been obtained, and (d)
the Notes shall have been duly executed by the Company and duly authenticated by
the trustee and delivered to the purchasers against payment of the agreed
consideration, the Notes when issued will be legally issued and binding
obligations of the Company.

         2. When any of the Conversion Shares shall have been issued in
accordance with the terms of the Indenture upon conversion of the Notes, the
Conversion Shares so issued will be legally issued, fully paid and
nonassessable.

         3. When any of the Provisional Redemption Shares shall have been issued
in accordance with the terms of the Indenture, the Provisional Redemption Shares
so issued will be legally issued, fully paid and nonassessable.

         4. When any of the Exchange Shares shall have been issued in accordance
with the terms described in the Registration Statement, the Exchange Shares so
issued will be legally issued, fully paid and nonassessable.

         Our opinions expressed above are subject to the qualifications that we
express no opinion as to the applicability of, compliance with or effect of (a)
any bankruptcy, insolvency, reorganization, fraudulent transfer, fraudulent
conveyance, moratorium or other similar laws affecting the enforcement of
creditors' rights generally, (b) general principles of equity (regardless of
whether enforcement is considered in a proceeding in equity or at law), (c)
public policy considerations which may limit the rights of parties to obtain
certain remedies and (d) other commonly recognized statutory and judicial
constraints on enforceability, including, without limitation, statutes of
limitations.

         Our advice on every legal issue addressed in this letter is based
exclusively on the internal law of the State of New York, the New Jersey
Business Corporation Act, constitution and reported judicial decisions of the
State of New Jersey or the federal law of the United States, and represents our
opinion as to how that issue would be resolved were it to be considered by the
highest court in the jurisdiction which enacted such law. The manner in which
any particular issue would be treated in any actual court case would depend in
part on facts and circumstances



EMCORE
January 21, 2004
Page 3


particular to the case and would also depend on how the court involved chose to
exercise the wide discretionary authority generally available to it. This letter
is not intended to guarantee the outcome of any legal dispute which may arise in
the future. We advise you that issues addressed by this letter may be governed
in whole or in part by other laws, but we express no opinion as to whether any
relevant difference exists between the laws upon which our opinions are based
and any other laws which may actually govern. We have assumed without
investigation that there has been no relevant change or development between the
date of such certificate and the date of this letter.

         We do not find it necessary for the purposes of this opinion, and
accordingly we do not purport to cover herein, the application of the securities
or "Blue Sky" laws of the various states to the issuance of the Securities.

         This opinion is furnished to you in connection with the filing of the
Registration Statement, and is not to be used, circulated, quoted or otherwise
relied upon for any other purposes. This opinion is limited to the specific
issues addressed herein, and no opinion may be inferred or implied beyond that
expressly stated herein. We assume no obligation to revise or supplement this
opinion should the present laws identified above be changed by legislative
action, judicial decision or otherwise.

         We hereby consent to the filing of this opinion as Exhibit 5 to the
Registration Statement. We also consent to the reference to our firm under the
heading "Legal Matters" in the Registration Statement. In giving this consent,
we do not thereby admit that we are in the category of persons whose consent is
required under Section 7 of the Securities Act or the rules and regulations of
the Commission.

                                    Very truly yours,


                                    /s/ Jenner & Block LLP

                                    Jenner & Block LLP