Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011
Cash flows from operating activities:
Net income	$ 6,209	$ 21,597
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	4,511	2,910
Stock-based compensation	3,054	1,777
Excess tax benefit from equity awards	(814)	(1,519)
Loss on disposal of fixed assets	134	3
Inventory write down	1,086	728
Deferred income taxes	995	1,425
Other, net	7
Changes in fair value of contingent payments to Zygo Corporation	9	391
Changes in assets and liabilities:
Accounts receivable	(11,141)	1,092
Inventories	(1,475)	(5,502)
Inventories-delivered systems	(229)	(969)
Prepaid expenses and other	(1,805)	(3,200)
Accounts payable, accrued and other liabilities	(3,060)	2,010
Deferred revenue	4,222	2,607
Income taxes payable	466	2,315
Net cash provided by operating activities	2,169	25,665
Cash flows from investing activities:
Escrow payment received related to acquisition of Nanda	508
Purchases of marketable securities	(13,764)
Purchases of property, plant and equipment	(2,635)	(1,746)
Net cash used in investing activities	(15,891)	(1,746)
Cash flows from financing activities:
Payments to Zygo Corporation related to acquisition	(198)	(191)
Repayments of debt obligations	(374)	(282)
Proceeds from sale of shares under employee stock option plans and purchase plan	2,632	3,539
Excess tax benefit from equity awards	814	1,519
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	(2,102)	282
Effect of exchange rate changes on cash and cash equivalents	115	1,024
Net increase (decrease) in cash and cash equivalents	(15,709)	25,225
Cash and cash equivalents, beginning of period	97,699	66,460
Cash and cash equivalents, end of period	$ 81,990	$ 91,685