Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended				9 Months Ended
	Oct. 01, 2011		Oct. 02, 2010		Oct. 01, 2011		Oct. 02, 2010
Revenue:
Product revenue	$ 109,993		$ 85,051		$ 304,100		$ 257,107
Contract revenue	10,380		9,172		30,632		29,850
Total revenue	120,373		94,223		334,732		286,957
Cost of revenue:
Cost of product revenue	63,670	[1]	54,472	[1]	177,695	[1]	165,897	[1]
Cost of contract revenue	6,660	[1]	6,494	[1]	21,004	[1]	21,116	[1]
Total cost of revenue	70,330		60,966		198,699		187,013
Gross margin	50,043		33,257		136,033		99,944
Operating expenses:
Research and development	8,948	[1]	6,185	[1]	25,823	[1]	16,375	[1]
Selling and marketing	14,553	[1]	10,734	[1]	40,301	[1]	30,959	[1]
General and administrative	10,962	[1]	8,904	[1]	31,659	[1]	26,693	[1]
Total operating expenses	34,463		25,823		97,783		74,027
Operating income	15,580		7,434		38,250		25,917
Other income (expense), net	(92)		299		258		368
Income before income taxes	15,488		7,733		38,508		26,285
Income tax expense	1,436		701		8,955		7,771
Net income	14,052		7,032		29,553		18,514
Net income per share
Basic	$ 0.52		$ 0.28		$ 1.11		$ 0.73
Diluted	$ 0.50		$ 0.27		$ 1.06		$ 0.70
Number of shares used in calculations per share
Basic	26,902		25,428		26,568		25,293
Diluted	27,940		26,480		27,823		26,319
Stock-based Compensation
Cost of revenue:
Cost of product revenue	344		310		915		997
Cost of contract revenue	115		101		365		337
Operating expenses:
Research and development	162		211		481		488
Selling and marketing	174		240		513		885
General and administrative	$ 1,401		$ 1,079		$ 4,112		$ 3,325

[1] Total stock-based compensation recorded in the three and nine months ended October 1, 2011 and October 2, 2010 included in the above figures breaks down by expense classification as follows: