Income Taxes - Additional Information (Details) - USD ($)		12 Months Ended
	Mar. 25, 2021	Oct. 02, 2021	Oct. 03, 2020	Sep. 28, 2019
Income Tax Examination [Line Items]
Effective tax rate on income before income taxes		7.60%	6.50%
Effective income tax rate reconciliation, at federal statutory income tax rate, percent		21.00%
Income taxes payable/receivable		$ 32,565,000	$ (25,024,000)	$ (119,929,000)
Valuation allowance, deferred tax asset, increase (decrease), amount		(15,500,000)
Valuation allowance		(73,166,000)	(57,707,000)
Operating loss carryforwards and tax credits		73,902,000	83,447,000
Unrecognized tax benefits, including interest and penalties		43,400,000
Unrecognized tax benefits that would impact effective tax rate		32,400,000
Unrecognized tax benefits, income tax penalties and interest accrued		3,600,000	2,900,000
Payments for Merger Related Costs		217,600,000
Lumentum Holdings Inc.
Income Tax Examination [Line Items]
Payments for Merger Related Costs	$ 217,600,000
Tax benefit credit to APIC when recognized
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, foreign		38,400,000
SINGAPORE
Income Tax Examination [Line Items]
Income taxes payable/receivable		3,700,000	$ 2,600,000	$ 3,900,000
Foreign Tax Authority
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits		132,900,000
Deferred tax assets, operating loss carryforwards, not subject to expiration		98,800,000
Deferred tax assets, operating loss carryforwards, subject to expiration		34,100,000
Operating loss carryforwards, valuation allowance		128,000,000
Federal Government
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits		10,100,000
State Government
Income Tax Examination [Line Items]
Operating loss carryforwards and tax credits		30,400,000
Internal Revenue Service (IRS) | Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research		38,400,000
CALIFORNIA
Income Tax Examination [Line Items]
Tax credit carryforward, valuation allowance		29,400,000
CALIFORNIA | Not Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research		34,900,000
Other states besides California
Income Tax Examination [Line Items]
Tax credit carryforward, valuation allowance		3,800,000
Other states besides California | Subject to Expiration Dates
Income Tax Examination [Line Items]
Deferred tax assets, tax credit carryforwards, research		$ 4,300,000
SINGAPORE
Income Tax Examination [Line Items]
The benefits of the tax holiday on net income per diluted share		$ 0.15	$ 0.11	$ 0.16