-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 RYuXnYttbDrh0sBcDIdtMklsJ4MD1mkmUf2wRTe4oEHMw7BL3jGHn8BZYyUR1/qY
 wL7Uw3ntRJpsZAfjhmxUsA==

<SEC-DOCUMENT>0001179110-04-015153.txt : 20040723
<SEC-HEADER>0001179110-04-015153.hdr.sgml : 20040723
<ACCEPTANCE-DATETIME>20040722180817
ACCESSION NUMBER:		0001179110-04-015153
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040719
FILED AS OF DATE:		20040722

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Meissner Paul L
		CENTRAL INDEX KEY:			0001298120

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-05255
		FILM NUMBER:		04927300

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(408) 764-4000

	MAIL ADDRESS:	
		STREET 1:		COHERENT, INC
		STREET 2:		PO BOX 54980
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95056-0980

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COHERENT INC
		CENTRAL INDEX KEY:			0000021510
		STANDARD INDUSTRIAL CLASSIFICATION:	LABORATORY ANALYTICAL INSTRUMENTS [3826]
		IRS NUMBER:				941622541
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		5100 PATRICK HENRY DR
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054
		BUSINESS PHONE:		4087644000

	MAIL ADDRESS:	
		STREET 1:		5100 PATRICK HENRY DRIVE
		STREET 2:		MAIL STOP P38
		CITY:			SANTA CLARA
		STATE:			CA
		ZIP:			95054

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COHERENT RADIATION
		DATE OF NAME CHANGE:	19770604
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 3 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-07-19</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000021510</issuerCik>
        <issuerName>COHERENT INC</issuerName>
        <issuerTradingSymbol>COHR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001298120</rptOwnerCik>
            <rptOwnerName>Meissner Paul L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P.O. BOX 54980</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SANTA CLARA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95056</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Exec VP, GM, Laser Systems</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Incentive Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.58</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-07-19</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-07-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>11286</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Non-Qualified Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.58</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-07-19</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-07-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>33714</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares become exercisable 3,762 shares on 7/19/05, 7/19/06, and 7/19/07 respectively.</footnote>
        <footnote id="F2">These shares become exercisable 11,238 shares 7/19/05, 7/19/06 and 7/19/07, respectively.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Scott H. Miller, by power of atty</signatureName>
        <signatureDate>2004-07-22</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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