Goodwill and Intangible Assets - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended
Jul. 04, 2020	Jun. 29, 2019
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 427,101
Impairment charges	(327,203)	$ 0
Translation adjustments	(1,251)
Goodwill, end of period	98,647
OEM Laser Sources
Goodwill [Roll Forward]
Goodwill, beginning of period	96,820
Impairment charges	0
Translation adjustments	1,827
Goodwill, end of period	98,647
Industrial Lasers & Systems
Goodwill [Roll Forward]
Goodwill, beginning of period	330,281
Impairment charges	(327,203)
Translation adjustments	(3,078)
Goodwill, end of period	$ 0

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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