UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 8)*

EMCORE Corporation

(Name of Issuer)

Common Stock

(Title of Class of Securities)

290846203

(CUSIP Number)

Northern Right Capital Management, L.P.

Attn: Chief Compliance Officer

10 Corbin Drive

3^rd Floor

Darien, Connecticut 06820

(203) 951-5440

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

November 23, 2015

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Section 240.13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

This Amendment No. 8 to Schedule 13D amends and supplements the Schedule 13D filed with the Securities and Exchange Commission (the “SEC”) on October 15, 2013, Amendment No. 1 thereto, filed with the SEC on October 29, 2013, Amendment No. 2 thereto, filed with the SEC on December 4, 2013, Amendment No. 3 thereto, filed with the SEC on December 6, 2013, Amendment No. 4 thereto, filed with the SEC on September 18, 2014, Amendment No. 5 thereto, filed with the SEC on August 12, 2015, Amendment No. 6 thereto, filed with the SEC on August 28, 2015, and Amendment No. 7 thereto, filed with the SEC on November 4, 2015, on behalf of the Reporting Persons (as defined below) with respect to the shares of common stock, no par value (the “Common Stock”), of EMCORE Corporation, a New Jersey corporation (the “Issuer”).

Item 2 is amended and supplemented to add the following information for updating as of the date hereof:

(a) This Statement is filed jointly on behalf of the following persons (collectively, the “Reporting Persons”): Northern Right Capital Management, L.P., a Texas limited partnership (“NRC Management”); Northern Right Capital (QP), L.P., a Texas limited partnership (“NRC QP”); Becker Drapkin Partners SLV, Ltd., a Cayman Island exempted company (“BD SLV”); BC Advisors, LLC, a Texas limited liability company (“BCA”); Steven R. Becker (“Mr. Becker”); and Matthew A. Drapkin (“Mr. Drapkin”). The Reporting Persons are filing this Statement jointly.

Item 5 is amended and supplemented to add the following information for updating as of the date hereof:

(a), (b) The Reporting Persons may be deemed to beneficially own in the aggregate 1,816,364 shares of Common Stock. Based upon a total of 25,563,888 outstanding shares of Common Stock, as reported in the Issuer’s quarterly report on Form 10-Q for the quarter ended June 30, 2015, the Reporting Persons’ shares represent approximately 7.105% of the outstanding shares of Common Stock.

NRC QP owns 552,797 shares of Common Stock (the “NRC QP Shares”), which represent approximately 2.162% of the outstanding shares of Common Stock. NRC QP has the power to vote or to direct the vote of (and the power to dispose or direct the disposition of) the NRC QP Shares. NRC QP disclaims beneficial ownership of the BD SLV Shares (as defined below) and the Managed Account Shares (as defined below).

BD SLV owns 788,384 shares of Common Stock (the “BD SLV Shares”), which represent approximately 3.084% of the outstanding shares of Common Stock. BD SLV has the power to vote or to direct the vote of (and the power to dispose or direct the disposition of) the BD SLV Shares. BD SLV disclaims beneficial ownership of the NRC QP Shares and the Managed Account Shares.

As general partner and investment manager of NRC QP and investment manager of BD SLV, NRC Management may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) the NRC QP Shares and BD SLV Shares. NRC Management disclaims beneficial ownership of the NRC QP Shares and BD SLV Shares. NRC Management in its capacity as investment manager for the Managed Account may be deemed to have the sole power to vote or direct the vote of (and the sole power to dispose or direct the disposition of) 467,607 shares held by the Managed Account (the “Managed Account Shares”), which represent approximately 1.829% of the outstanding shares of Common Stock.

As general partner of NRC Management, BCA may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) any shares of Common Stock beneficially owned by NRC Management. BCA disclaims beneficial ownership of any shares of Common Stock beneficially owned by NRC Management.

As a member of BCA and pursuant to the operating agreement of BCA, Mr. Drapkin may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) any shares of Common Stock beneficially owned by BCA. Mr. Drapkin disclaims beneficial ownership of any shares of Common Stock beneficially owned by BCA.

As a member of BCA and pursuant to the operating agreement of BCA, Mr. Becker may be deemed to have the shared power to vote or direct the vote of (and the shared power to dispose or direct the disposition of) the BD SLV Shares and the Managed Account Shares. Mr. Becker disclaims beneficial ownership of any shares of Common Stock beneficially owned by BCA. Mr. Becker directly beneficially owns 7,576 shares of Common Stock of the Issuer, which represent approximately 0.030% of the outstanding shares of Common Stock and were acquired pursuant to the Issuer’s 2007 Directors’ Stock Award Plan for Mr. Becker’s service as a non-employee director. All Reporting Persons, except for Mr. Becker, disclaim beneficial ownership of the 7,576 shares of Common Stock directly beneficially owned by Mr. Becker.

As of the date hereof, no Reporting Person owns any shares of Common Stock other than those set forth in this Item 5.

(c) The trading dates, number of shares of Common Stock purchased or sold, and the price per share of Common Stock for all transactions by the Reporting Persons in shares of Common Stock since the Reporting Persons filed Amendment No. 7 to the Original Schedule 13D are set forth in the chart below. All transactions listed below were made pursuant to the 10b5-1 Plans.

(d) No person other than the Reporting Persons, and the Managed Account with respect to the Managed Account Shares, has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of common Stock set forth above.

(e) Not applicable.

SIGNATURES

After reasonable inquiry and to the best of each of the undersigned’s knowledge and belief, each of the undersigned, severally and not jointly, certified that the information set forth in this statement is true, complete and correct.

Dated: November 24, 2015