<SUBMISSION>
<ACCESSION-NUMBER>0001181431-06-069156
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20061212
<FILING-DATE>20061212
<DATE-OF-FILING-DATE-CHANGE>20061212
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>IPG PHOTONICS CORP
<CIK>0001111928
<ASSIGNED-SIC>3674
<IRS-NUMBER>043444218
<STATE-OF-INCORPORATION>DE
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>50 OLD WEBSTER ROAD
<CITY>OXFORD
<STATE>MA
<ZIP>01540
<PHONE>5083731100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>50 OLD WEBSTER ROAD
<CITY>OXFORD
<STATE>MA
<ZIP>01540
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA ASSOCIATES AP IV LP
<CIK>0001235813
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-33155
<FILM-NUMBER>061272434
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>rrd139128.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-12-12</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001111928</issuerCik>
        <issuerName>IPG PHOTONICS CORP</issuerName>
        <issuerTradingSymbol>IPGP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235813</rptOwnerCik>
            <rptOwnerName>TA ASSOCIATES AP IV LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST. 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2006-12-12</value>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>328515</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 3</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2006-12-12</value>
            </exerciseDate>
            <expirationDate>
                <value>2008-04-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 3</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The number of shares of Common Stock is subject to adjustment based upon the initial public offering price in connection with the issuer's initial public offering.</footnote>
        <footnote id="F2">The number of shares of Common Stock underlying the warrants is indeterminate and will be determined based upon the initial public offering price of the Common Stock in connection with the issuer's initial public offering.</footnote>
        <footnote id="F3">The reporting person may be deemed to have an indirect pecuniary interest as the General Partner of TA/Atlantic and Pacific IV L.P.  The reporting person disclaims benefical ownership of such shares because the reporting person's indirect pecuniary interest is subject to indeterminable future events.</footnote>
        <footnote id="F4">N/A</footnote>
    </footnotes>

    <remarks>The Reporting Person has a representative on the issuer's board of directors.  Michael Child currently serves as the Reporting Person's representative on the board of directors and the Reporting Person is deemed a director of the issuer by deputization.</remarks>

    <ownerSignature>
        <signatureName>By: TA Associates AP IV L.P.</signatureName>
        <signatureDate>2006-12-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: TA Associates, Inc., its General Partner</signatureName>
        <signatureDate>2006-12-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>By: Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2006-12-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
