Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Cash flows from operating activities:
Net income	$ 4,465	$ 28,685	$ 55,948
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization	8,137	4,983	4,395
Asset impairment	0	0	463
Stock-based compensation	5,890	4,473	2,950
Excess tax benefit from equity awards	(910)	(3,915)	(801)
Loss on disposal of fixed assets	303	113	(140)
Inventory write down	3,519	3,421	2,920
Deferred income taxes	2,752	3,770	(17,233)
Other, net	0	0	(523)
Changes in fair value of contingent payments to Zygo Corporation	129	413	467
Changes in assets and liabilities:
Accounts receivable	7,733	16,172	(20,996)
Inventories	1,383	(12,169)	(14,495)
Inventories-delivered systems	(758)	446	244
Prepaid expenses and other	1,114	(4,747)	(398)
Accounts payable, accrued and other liabilities	(12,567)	4,241	11,533
Deferred revenue	2,472	3,088	1,414
Income taxes payable	346	5,054	1,879
Net cash provided by operating activities	24,008	54,028	27,627
Cash flows from investing activities:
Escrow payment received related to Nanda acquisition	508	0	0
Purchase of Nanda's net assets, net of cash received	0	(23,912)	0
Sales of marketable securities	3,000	0	0
Maturities of marketable securities	8,336	0	0
Purchases of marketable securities	(58,647)	0	0
Purchases of property, plant and equipment	(4,990)	(2,755)	(3,096)
Proceeds from sale of property, plant and equipment	0	0	492
Net cash used in investing activities	(51,793)	(26,667)	(2,604)
Cash flows from financing activities:
Payments to Zygo Corporation related to acquisition	(300)	(432)	(3,503)
Repayments of debt obligations	(2,210)	(2,571)	(2,999)
Proceeds from sale of shares under employee stock option plans and purchase plan	3,913	7,186	5,784
Stock offering cost	0	0	(28)
Excess tax benefit from equity awards	910	3,915	801
Taxes paid on net issuance of stock awards	(618)	(126)	(299)
Repurchases of common stock	(8,504)	(4,257)	(2,097)
Net cash provided by (used in) financing activities	(6,809)	3,715	(2,341)
Effect of exchange rate changes on cash and cash equivalents	(190)	163	252
Net increase (decrease) in cash and cash equivalents	(34,784)	31,239	22,934
Cash and cash equivalents, beginning of period	97,699	66,460	43,526
Cash and cash equivalents, end of period	62,915	97,699	66,460
Supplemental disclosure of cash flow information:
Cash paid for interest	522	757	965
Cash paid for income taxes	$ 5,113	$ 11,149	$ 1,572