Operating Segments and Geographic Information - Segments Utilized by our CODM (Details) $ in Millions	3 Months Ended	6 Months Ended
Dec. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 30, 2017 USD ($) segment	Dec. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments \| segment			2
Information on reportable segments
Net revenue	$ 404.6	$ 265.0	$ 647.8	$ 523.1
Gross profit	171.1	87.0	239.6	168.7
Gross Profit	171.1	87.0	239.6	168.7
Operating Segments
Information on reportable segments
Net revenue	404.6	265.0	647.8	523.1
Gross profit	181.8	97.9	264.5	186.1
Gross Profit	181.8	97.9	264.5	186.1
Operating Segments \| OpComms
Information on reportable segments
Net revenue	360.1	236.6	568.0	454.9
Gross profit	161.9	86.7	234.0	157.7
Gross Profit	161.9	86.7	234.0	157.7
Operating Segments \| Lasers
Information on reportable segments
Net revenue	44.5	28.4	79.8	68.2
Gross profit	19.9	11.2	30.5	28.4
Gross Profit	19.9	11.2	30.5	28.4
Corporate
Information on reportable segments
Stock-based compensation	(4.4)	(2.1)	(7.1)	(4.1)
Amortization of intangibles	(0.8)	(1.7)	(1.6)	(3.4)
Other charges related to non-recurring activities	$ (5.5)	$ (7.1)	$ (16.2)	$ (9.9)

The aggregate expense charged against earnings related to acquisition-related charges and amortization of intangibles.

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Represents the expense from continuing operations recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Represents the other charges related to non-recurring activities charged to earnings during the year.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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