Stock Based Compensation Expense (Detail) (USD $)	3 Months Ended		6 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 41,000	$ 49,000	$ 70,000	$ 78,000
Cost of Products Sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	2,000	4,000	4,000	7,000
Research, Development, and Engineering Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	7,000	16,000	12,000	23,000
General and Administrative expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	24,000	24,000	39,000	41,000
Sales and Marketing Expense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock based compensation expense	$ 8,000	$ 5,000	$ 15,000	$ 7,000