Revenue (Tables)

3 Months Ended

Mar. 30, 2019

Disaggregation of Revenue from Contracts with Customers

The following tables represent a disaggregation of revenue from contracts with customers for the three months ended March 30, 2019 and March 31, 2018 along with the reportable segment for each category.

Major Products and Service Lines

TFE	Three Months Ended March 30, 2019								Three Months Ended March 31, 2018
	(In thousands)
	HDD		DCP		PV		Total		HDD		DCP		PV		Total
Systems, upgrades and spare parts	$	11,050	$	—	$	6,373	$	17,423	$	10,393	$	1	$	2	$	10,396
Field service		1,522		—		—		1,522		2,355		—		38		2,393
Total TFE net revenues	$	12,572	$	—	$	6,373	$	18,945	$	12,748	$	1	$	40	$	12,789

	Three Months Ended
Photonics	March 30, 2019		March 31, 2018
	(In thousands)
Products:
Military products	$	1,813	$	2,254
Commercial products		318		—
Repair and other services		561		429
Total Photonics product net revenues		2,692		2,683
Technology development:
Firm Fixed Price (“FFP”)		1,692		692
Cost Plus Fixed Fee (“CPFF”)		1,496		1,790
Time and materials		2		20
Total technology development net revenues		3,190		2,502
Total Photonics net revenues	$	5,882	$	5,185

Primary Geographical Markets

	Three Months Ended
	March 30, 2019						March 31, 2018
	(In thousands)
	TFE		Photonics		Total		TFE		Photonics		Total
United States	$	161	$	5,716	$	5,877	$	1,911	$	4,762	$	6,673
Asia		18,784		—		18,784		10,878		—		10,878
Europe		—		166		166		—		293		293
Rest of World		—		—		—		—		130		130
Total net revenues	$	18,945	$	5,882	$	24,827	$	12,789	$	5,185	$	17,974

Timing of Revenue Recognition

	Three Months Ended
	March 30, 2019						March 31, 2018
	(In thousands)
	TFE		Photonics		Total		TFE		Photonics		Total
Products transferred at a point in time	$	18,945	$	561	$	19,506	$	12,789	$	429	$	13,218
Products and services transferred over time		—		5,321		5,321		—		4,756		4,756
	$	18,945	$	5,882	$	24,827	$	12,789	$	5,185	$	17,974

Changes in Contract Assets and Contract Liabilities

The following table reflects the changes in our contract assets, which we classify as accounts receivable, unbilled or retainage, and our contract liabilities, which we classify as deferred revenue and customer advances, for the three months ended March 30 2019.

	March 30, 2019		December 29, 2018		Three Months Change
	(In thousands)
TFE:
Contract assets:
Accounts receivable, unbilled	$	897	$	514	$	383
Contract liabilities:
Deferred revenue	$	713	$	633	$	80
Customer advances		10,335		14,314		(3,979	)
	$	11,048	$	14,947	$	(3,899	)
Photonics:
Contract assets:
Accounts receivable, unbilled	$	2,561	$	1,493	$	1,068
Retainage		131		157		(26	)
	$	2,692	$	1,650	$	1,042
Contract liabilities:
Deferred revenue	$	784	$	1,101	$	(317	)