Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011
Cash flows from operating activities:
Net income	$ 8,112	$ 29,216
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	7,143	4,722
Stock-based compensation	4,535	2,746
Excess tax benefit from equity awards	(939)	(1,925)
Loss on disposal of fixed assets	246	19
Inventory write down	1,450	1,294
Deferred income taxes	2,948	2,386
Changes in fair value of contingent payments to Zygo Corporation	307	434
Changes in assets and liabilities:
Accounts receivable	(831)	(259)
Inventories	(429)	(11,209)
Inventories-delivered systems	(571)	(477)
Prepaid expenses and other	(1,655)	130
Accounts payable, accrued and other liabilities	(12,242)	2,889
Deferred revenue	4,418	3,313
Income taxes payable	283	2,131
Net cash provided by operating activities	12,775	35,410
Cash flows from investing activities:
Escrow payment received related to Nanda acquisition	508	0
Sales of marketable securities	3,000	0
Maturities of marketable securities	500	0
Purchases of marketable securities	(40,929)	0
Purchases of property, plant and equipment	(3,705)	(2,082)
Net cash used in investing activities	(40,626)	(2,082)
Cash flows from financing activities:
Payments to Zygo Corporation related to acquisition	(232)	(301)
Repayments of debt obligations	(1,989)	(2,389)
Proceeds from sale of shares under employee stock option plans and purchase plan	3,463	5,291
Excess tax benefit from equity awards	939	1,925
Taxes paid on net issuance of stock awards	(16)	(46)
Repurchases of common stock	(4,960)	(4,257)
Net cash provided by (used in) financing activities	(2,795)	223
Effect of exchange rate changes on cash and cash equivalents	411	138
Net increase (decrease) in cash and cash equivalents	(30,235)	33,689
Cash and cash equivalents, beginning of period	97,699	66,460
Cash and cash equivalents, end of period	$ 67,464	$ 100,149