Business Combinations (Details) - USD ($) $ in Thousands			1 Months Ended	12 Months Ended
	Apr. 16, 2015	Jan. 02, 2015	Nov. 30, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Acquisition and asset sale related costs				$ 427	$ 130	$ 2,125
Tunable Laser Product Lines From EMCORE Corporation
Business Acquisition [Line Items]
Purchase price	$ 16,982	$ 17,500
Cash consideration paid	1,500	1,500
Issuance of notes to the seller of acquired business	$ 15,482	$ 16,000
Acquisition and asset sale related costs							$ 900
EigenLight Corporation
Business Acquisition [Line Items]
Cash consideration paid			$ 400