Information for Each Reportable Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Segment Reporting Information [Line Items]
Total segment net revenues	$ 17,015	$ 12,982
Unallocated costs	(1,491)	(1,282)
Loss on divestitures		(208)
Loss from operations	(4,724)	(9,023)
Interest income and other, net	73	80
Loss before income taxes	(4,651)	(8,943)
Operating Segments
Segment Reporting Information [Line Items]
Loss from operations	(3,233)	(7,533)
Equipment
Segment Reporting Information [Line Items]
Total segment net revenues	9,047	5,368
Equipment | Operating Segments
Segment Reporting Information [Line Items]
Loss from operations	(4,141)	(7,341)
Photonics
Segment Reporting Information [Line Items]
Total segment net revenues	7,968	7,614
Photonics | Operating Segments
Segment Reporting Information [Line Items]
Loss from operations	$ 908	$ (192)