Operating Segments and Geographic Information - Schedule of Information on Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended
Sep. 29, 2018	Sep. 30, 2017
Information on reportable segments
Net revenue	$ 354.1	$ 243.2
Gross profit	126.0	68.5
Stock-based compensation	(10.8)	(9.3)
Amortization of intangibles	(0.8)	(0.8)
Gross profit	126.0	68.5
Operating segments
Information on reportable segments
Net revenue	354.1	243.2
Gross profit	142.6	82.7
Gross profit	142.6	82.7
Operating segments \| OpComms
Information on reportable segments
Net revenue	310.1	207.9
Gross profit	124.9	72.1
Gross profit	124.9	72.1
Operating segments \| Lasers
Information on reportable segments
Net revenue	44.0	35.3
Gross profit	17.7	10.6
Gross profit	17.7	10.6
Unallocated corporate items
Information on reportable segments
Stock-based compensation	(3.3)	(2.7)
Amortization of intangibles	(0.8)	(0.8)
Other charges	(12.5)	(10.7)
Inventory write-downs		7.0
Unallocated corporate items \| Thailand
Information on reportable segments
Other charges	$ (12.7)	$ (3.1)

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