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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001145443-11-000113.txt : 20110201
<SEC-HEADER>0001145443-11-000113.hdr.sgml : 20110201
<ACCEPTANCE-DATETIME>20110201175323
ACCESSION NUMBER:		0001145443-11-000113
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110128
FILED AS OF DATE:		20110201
DATE AS OF CHANGE:		20110201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Larocca Christopher M
		CENTRAL INDEX KEY:			0001465498

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22175
		FILM NUMBER:		11564283

	MAIL ADDRESS:	
		STREET 1:		10420 RESEARCH ROAD SE
		CITY:			ALBUQUERQUE
		STATE:			NM
		ZIP:			87123

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			EMCORE CORP
		CENTRAL INDEX KEY:			0000808326
		STANDARD INDUSTRIAL CLASSIFICATION:	SEMICONDUCTORS & RELATED DEVICES [3674]
		IRS NUMBER:				222746503
		STATE OF INCORPORATION:			NJ
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		10420 RESEARCH ROAD, SE
		CITY:			ALBUQUERQUE
		STATE:			NM
		ZIP:			87123
		BUSINESS PHONE:		505-332-5000

	MAIL ADDRESS:	
		STREET 1:		10420 RESEARCH ROAD, SE
		CITY:			ALBUQUERQUE
		STATE:			NM
		ZIP:			87123
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>d27841.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-01-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000808326</issuerCik>
        <issuerName>EMCORE CORP</issuerName>
        <issuerTradingSymbol>EMKR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001465498</rptOwnerCik>
            <rptOwnerName>Larocca Christopher M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10420 RESEARCH ROAD SE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALBUQUERQUE</rptOwnerCity>
            <rptOwnerState>NM</rptOwnerState>
            <rptOwnerZipCode>87123</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Operating Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-01-28</value>
            </transactionDate>
            <deemedExecutionDate>
                <footnoteId id="F1"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>70000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.42</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>102819</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18896</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Vests in three equal annual installments beginning on January 28, 2012.</footnote>
        <footnote id="F2">Shares attributable to EMCORE Corporation 401(k) account as of January 31, 2011. Note that 10,000 shares attributable to EMCORE Corporation 401(k) account owned by the reporting person were unintentionally omitted from the Form 4 filed on March 24, 2010.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Christopher Larocca</signatureName>
        <signatureDate>2011-02-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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