Revenues from contracts with customers - Schedule of Revenues by End Market (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 27, 2025	Jun. 28, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 3,419,327	$ 2,882,967	$ 2,645,237
Product Concentration Risk \| Revenue from Contract with Customer Benchmark
Disaggregation of Revenue [Line Items]
Revenues, as a percentage of total revenues	100.00%	100.00%	100.00%
Optical communications
Disaggregation of Revenue [Line Items]
Revenues	$ 2,619,355	$ 2,289,015	$ 2,008,347
Optical communications \| Product Concentration Risk \| Revenue from Contract with Customer Benchmark
Disaggregation of Revenue [Line Items]
Revenues, as a percentage of total revenues	76.60%	79.40%	75.90%
Optical communications \| Datacom
Disaggregation of Revenue [Line Items]
Revenues	$ 1,155,944	$ 1,150,307	$ 520,796
Optical communications \| Telecom
Disaggregation of Revenue [Line Items]
Revenues	1,463,411	1,138,708	1,487,551
Non-optical communications
Disaggregation of Revenue [Line Items]
Revenues	$ 799,972	$ 593,952	$ 636,890
Non-optical communications \| Product Concentration Risk \| Revenue from Contract with Customer Benchmark
Disaggregation of Revenue [Line Items]
Revenues, as a percentage of total revenues	23.40%	20.60%	24.10%
Non-optical communications \| Automotive
Disaggregation of Revenue [Line Items]
Revenues	$ 464,369	$ 327,188	$ 368,581
Non-optical communications \| Industrial laser
Disaggregation of Revenue [Line Items]
Revenues	153,068	122,722	125,415
Non-optical communications \| Others
Disaggregation of Revenue [Line Items]
Revenues	$ 182,535	$ 144,042	$ 142,894