Commitments and Contingencies - Schedule of Non-cancellable Operating Leases Minimum Payments (Details) (Parenthetical) - USD ($) $ in Thousands  | 
6 Months Ended | |
|---|---|---|
Mar. 28, 2021  | 
Sep. 27, 2020  | 
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| Commitments and Contingencies Disclosure [Abstract] | ||
| Borrowing discount rate | 5.00% | |
| Lease options exercised description | Assumes a discount borrowing rate of 5.0% on the new lease amendments effective as of January 11, 2021 and 7.5% on the remaining lease term for the Applied Optics Dallas facility through October 31, 2021. | |
| Short-term operating lease | $ 477 | $ 417 | 
| Long-term operating lease | 3,374 | $ 1,037 | 
| Rent | $ 11 | |
| Lease term expiring | Oct. 31, 2021 | 
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- Definition Lease options exercised description. No definition available. 
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- References No definition available. 
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- Definition Date which lease or group of leases is set to expire, in YYYY-MM-DD format. No definition available. 
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- Definition Discount rate used by lessee to determine present value of operating lease payments. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Cash payments to lessor's for use of assets under operating leases. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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