FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * GAPONTSEV VALENTIN P   2. Issuer Name and Ticker or Trading Symbol IPG PHOTONICS CORP [IPGP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO & Chairman of the Board (Last) (First) (Middle) C/O IPG PHOTONICS CORPORATION, 50 OLD WEBSTER ROAD 3. Date of Earliest Transaction (Month/Day/Year) 12/02/2011 (Street) OXFORD, MA 01540 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 12/02/2011   S   1,607 D $ 41.44 (1) 1,901,324 D   Common Stock 12/02/2011   S   4,875 D $ 41.44 (2) 7,499,127 I Through IP Fibre Devices (UK) Ltd. (5) Common Stock 12/05/2011   S   20,514 D $ 41.29 (3) 1,880,810 D   Common Stock 12/05/2011   S   62,265 D $ 41.29 (4) 7,436,862 I Through IP Fibre Devices (UK) Ltd. (5) Common Stock 12/06/2011   S   27,879 D $ 39.95 1,852,931 D   Common Stock 12/06/2011   S   82,860 D $ 39.95 7,354,002 I Through IP Fibre Devices (UK) Ltd. (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GAPONTSEV VALENTIN P C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD, MA 01540	X	X	CEO & Chairman of the Board
Valentin Gapontsev Trust I C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD, MA 01540		X
Shcherbakov Eugene A C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD, MA 01540	X	X	Managing Director of IPG Laser
IP FIBRE DEVICES LTD C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD, MA 01540		X
PLATONOV NIKOLAI C/O IPG PHOTONICS CORPORATION 50 OLD WEBSTER ROAD OXFORD, MA 01540		X

Signatures

Angelo P. Lopresti, Attorney-in-fact for Valentin Gapontsev		12/06/2011
**Signature of Reporting Person		Date
By: Angelo P. Lopresti, Attorney-in-fact for IP Fibre Devices (UK) Ltd.		12/06/2011
**Signature of Reporting Person		Date
By: Angelo P. Lopresti, Attorney-in-fact for Valentin Gapontsev Trust I		12/06/2011
**Signature of Reporting Person		Date
By: Angelo P. Lopresti, Attorney-in-fact for N. Platonov		12/06/2011
**Signature of Reporting Person		Date
By: Angelo P. Lopresti, Attorney-in-fact for E. Scherbakov		12/06/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The reported transaction involved sales transactions from $41.25 to $41.74 per share. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer information regarding the number of shares sold at each separate price.
(2)	The reported transaction involved sales transactions from $41.25 to $41.73 per share. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer information regarding the number of shares sold at each separate price.
(3)	The reported transaction involved sales transactions from $40.68 to $41.72 per share. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer information regarding the number of shares sold at each separate price.
(4)	The reported transaction involved sales transactions from $40.68 to $41.72 per share. The Reporting Person undertakes to provide upon request by the SEC staff, the Issuer or a security holder of the Issuer information regarding the number of shares sold at each separate price.
(5)	These shares are owned directly by IP Fibre Devices (UK) Ltd. (IPFD), and indirectly by (i) Valentin P. Gapontsev, the managing director and a 5% shareholder of IPFD, (ii) the Valentin Gapontsev Trust I, a 48% shareholder of IPFD (Gapontsev Trust I), (iii) Nikolai Platonov, a trustee of Gapontsev Trust I and an 8% shareholder of IPFD, and (iv) Eugene Scherbakov, a trustee of Gapontsev Trust I and an 8% shareholder of IPFD. On May 20, 2011, Eugene Scherbakov was appointed as a trustee of Gapontsev Trust I. Drs. Gapontsev, Platonov and Scherbakov and Gapontsev Trust I each disclaim ownership of the securities directly owned by IPFD except to the extent of his or its pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1034, as amended, or for any other purpose.

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