Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Oct. 03, 2015	Sep. 28, 2013	Sep. 27, 2014	Sep. 30, 2009	Sep. 30, 2003
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 109,513
Additions	1,119
Translation adjustments and other	(8,815)	$ (3,895)
Goodwill, end of period	101,817	113,408
Commercial Lasers and Components
Goodwill [Roll Forward]
Goodwill, beginning of period	6,363
Additions	0
Translation adjustments and other	0	0
Goodwill, end of period	6,363	6,363
Goodwill, Gross	25,700
Accumulated impairment loss				$ 19,300
Specialty Laser Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	103,150
Additions	1,119
Translation adjustments and other	(8,815)	(3,895)
Goodwill, end of period	95,454	$ 107,045
Goodwill, Gross	$ 97,800		$ 105,500
Accumulated impairment loss					$ 2,400