Segment and Geographic Information - Sales and Income (Loss) from Operations (Details) $ in Thousands	3 Months Ended
	Jan. 01, 2022 USD ($) segments	Jan. 02, 2021 USD ($)
Segment Reporting [Abstract]
Number of reporting segments | segments	2
Segment Reporting Information [Line Items]
Net sales	$ 384,507	$ 326,053
Total income from operations	42,479	16,950
Total other expense, net	(6,185)	(2,289)
Income before income taxes	36,294	14,661
OEM Laser Sources
Segment Reporting Information [Line Items]
Net sales	242,970	211,162
Income (loss) from operations:	72,829	49,416
Industrial Lasers & Systems
Segment Reporting Information [Line Items]
Net sales	141,537	114,891
Income (loss) from operations:	12,252	(7,912)
Corporate and other
Segment Reporting Information [Line Items]
Income (loss) from operations:	$ (42,602)	$ (24,554)