Operating Segments and Geographic Information - Information on Reportable Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 02, 2022 USD ($)	Apr. 03, 2021 USD ($)	Apr. 02, 2022 USD ($) segment	Apr. 03, 2021 USD ($)
Information on reportable segments
Number of broad business categories (in segment) | segment			2
Total net revenue	$ 315.5	$ 303.4	$ 957.1	$ 888.0
Gross profit	$ 186.9	$ 182.0	$ 572.4	$ 531.5
Gross margin (as a percent)	59.20%	60.00%	59.80%	59.90%
Operating income	$ 40.8	$ 35.9	$ 137.0	$ 109.5
Operating margin (as a percent)	12.90%	11.80%	14.30%	12.30%
Other Items
Information on reportable segments
Total net revenue	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Gross profit	(8.7)	(9.4)	(26.8)	(28.0)
Operating income	(26.9)	(25.5)	(78.3)	(79.3)
Network and Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	230.8	211.2	702.9	601.4
Gross profit	$ 148.6	$ 135.5	$ 455.4	$ 384.2
Gross margin (as a percent)	64.40%	64.20%	64.80%	63.90%
Operating income	$ 34.4	$ 20.9	$ 110.7	$ 56.4
Operating margin (as a percent)	14.90%	9.90%	15.70%	9.40%
Network and Service Enablement | Network Enablement | Segment Measures
Information on reportable segments
Total net revenue	$ 204.3	$ 190.9	$ 623.6	$ 533.9
Gross profit	$ 130.3	$ 123.1	$ 401.0	$ 339.9
Gross margin (as a percent)	63.80%	64.50%	64.30%	63.70%
Network and Service Enablement | Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	$ 26.5	$ 20.3	$ 79.3	$ 67.5
Gross profit	$ 18.3	$ 12.4	$ 54.4	$ 44.3
Gross margin (as a percent)	69.10%	61.10%	68.60%	65.60%
Optical Security and Performance Products | Segment Measures
Information on reportable segments
Total net revenue	$ 84.7	$ 92.2	$ 254.2	$ 286.6
Gross profit	$ 47.0	$ 55.9	$ 143.8	$ 175.3
Gross margin (as a percent)	55.50%	60.60%	56.60%	61.20%
Operating income	$ 33.3	$ 40.5	$ 104.6	$ 132.4
Operating margin (as a percent)	39.30%	43.90%	41.10%	46.20%
Product revenue
Information on reportable segments
Total net revenue	$ 275.8	$ 266.6	$ 842.3	$ 776.6
Product revenue | Other Items
Information on reportable segments
Total net revenue	0.0	0.0	0.0	0.0
Product revenue | Network and Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	191.2	174.4	588.5	490.6
Product revenue | Network and Service Enablement | Network Enablement | Segment Measures
Information on reportable segments
Total net revenue	176.7	166.5	545.9	462.1
Product revenue | Network and Service Enablement | Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	14.5	7.9	42.6	28.5
Product revenue | Optical Security and Performance Products | Segment Measures
Information on reportable segments
Total net revenue	84.6	92.2	253.8	286.0
Service revenue
Information on reportable segments
Total net revenue	39.7	36.8	114.8	111.4
Service revenue | Other Items
Information on reportable segments
Total net revenue	0.0	0.0	0.0	0.0
Service revenue | Network and Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	39.6	36.8	114.4	110.8
Service revenue | Network and Service Enablement | Network Enablement | Segment Measures
Information on reportable segments
Total net revenue	27.6	24.4	77.7	71.8
Service revenue | Network and Service Enablement | Service Enablement | Segment Measures
Information on reportable segments
Total net revenue	12.0	12.4	36.7	39.0
Service revenue | Optical Security and Performance Products | Segment Measures
Information on reportable segments
Total net revenue	$ 0.1	$ 0.0	$ 0.4	$ 0.6