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 * SOBEY MARK STEWART   2. Issuer Name and Ticker or Trading Symbol COHERENT INC [COHR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP (Last) (First) (Middle) 5100 PATRICK HENRY DRIVE 3. Date of Earliest Transaction (Month/Day/Year) 11/13/2018 (Street) SANTA CLARA, CA 95054 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ 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 11/13/2018   M   2,868 A $ 0 7,932 D   Common Stock 11/13/2018   F   992 (1) D $ 123.26 6,940 D   Common Stock 11/13/2018   M   4,302 A $ 0 11,242 D   Commonn Stock 11/13/2018   A   4,302 (2) A $ 0 15,544 D   Common Stock 11/13/2018   F   3,644 (1) D $ 123.26 11,900 D   Common Stock 11/13/2018   A   4,118 (3) A $ 0 16,018 (4) D

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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

Restricted Stock Units

$ 0

11/13/2018

M

2,868

11/13/2018

11/13/2018

Common Stock

2,868

$ 0

12,420

D

Performance Restricted Stock Units

$ 0

11/13/2018

M

4,302

(5)

11/13/2018

Common Stock

4,302

$ 0

8,118

D

Performance Restricted Stock Unit

$ 0

11/13/2018

A

3,978

(6)

11/13/2021

Common Stock

3,978

$ 0

3,978

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SOBEY MARK STEWART 5100 PATRICK HENRY DRIVE SANTA CLARA, CA 95054			EVP

Signatures

/s/ Rhonda Fassbender, pursuant to Power of Attorney		11/15/2018
**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)	Represents shares withheld to satisfy minimum tax withholding obligations for released restricted stock units.
(2)	Additional shares acquired pursuant to the maximum achievement of the performance criteria beyond the target number, as described in footnote (5) on Table II.
(3)	On November 13, 2018 the Reporting Person was granted 4,118 Restricted Stock Units which will vest in three equal installments on each of November 13, 2019, November 13, 2020 and November 13, 2021.
(4)	Includes 5,982 Restricted Stock Units.
(5)	This Performance Restricted Stock Unit award vested on the three year anniversary of the grant based on the relative performance of the underlying stock versus the Russell 2000 Index for the 90 trading days on and prior to November 13, 2018 versus the same 90 trading day period ending November 13, 2015. The number of shares in the table reflects the target number of achieved RSUs. The actual range of RSUs was 0-200% of the target number, depending upon the achievement results at the measurement date.
(6)	This Performance Restricted Stock Unit award vests after the three year anniversary of the grant based on the relative performance of the underlying stock versus the Russell 1000 Index for the 90 trading days on and prior to November 13, 2021 versus the same 90 trading day period ending November 13, 2018. The number of shares in the table reflects the number of RSUs at target. The actual range of RSUs is 0-200% of the target number, depending upon what achievement, if any, results at the measurement date.

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