POWER OF ATTORNEY


       Know all by these presents that the undersigned hereby
constitutes and appoints Glenn E. Davis, Principal Financial Officer and
Anthony J. Bellantuoni, Vice President of Human Resources of GSI
Group Inc. his true and lawful attorneys-in-fact to:
(1)	execute for and on behalf of the undersigned
Forms 3, 4 and 5 in accordance with Section
16(a) of the Securities Exchange Act of 1934, as
amended, and the rules thereunder;
(2)	do and perform any and all acts for and on
behalf of the undersigned which may be
necessary or desirable to complete the execution
of any such Form 3, 4 and 5 and timely filing of
such forms with the United States Securities and
Exchange Commission and any other authority;
and
(3)	take any other action of any type whatsoever in
connection with the foregoing which, in the
opinion of such attorneys-in-fact, may be of
benefit to, in the best interest of, or legally
required by, the undersigned, it being
understood that the documents executed by such
attorneys-in-fact on behalf of the undersigned
pursuant to this Power of Attorney shall be in
such form and shall contain such terms and
conditions as such attorneys-in-fact may approve
in their discretion.
       The undersigned hereby grants to each attorney-in-fact,
individually, full power and authority to do and perform all and every act
and thing whatsoever requisite, necessary and proper to be done in the
exercise of any of the rights and powers herein granted, as fully to all
intents and purposes as each attorney-in-fact might or could do if
personally present, with full power of substitution or revocation, hereby
ratifying and confirming that each attorney-in-fact, or his substitute or
substitutes, shall lawfully do or cause to be done by virtue of this power
of attorney and the rights and powers herein granted.  The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving in such
capacity at the request of the undersigned, are not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934, as amended.
       IN WITNESS WHEREOF, the undersigned has caused this
Power of Attorney to be executed as of this 22nd day of December,
2010.


	/s/ John A. Roush
	Signature

	John A. Roush
	Print Name