Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income (loss)	$ (14,146)	$ 4,465	$ 28,685
Reconciliation of net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	8,787	8,137	4,983
Stock-based compensation	7,674	5,890	4,473
Excess tax benefit from equity awards	53	(910)	(3,915)
Loss on disposal of fixed assets	177	303	113
Inventory write down	7,579	3,519	3,421
Deferred income taxes	(6,889)	2,752	3,770
Changes in fair value of contingent payments to Zygo Corporation	1,325	129	413
Changes in assets and liabilities:
Accounts receivable	(10,376)	7,733	16,172
Inventories	(7,024)	1,383	(12,169)
Inventories-delivered systems	(4,627)	(758)	446
Prepaid expenses and other	(1,855)	1,114	(4,747)
Accounts payable, accrued and other liabilities	4,840	(12,567)	4,241
Deferred revenue	12,717	2,472	3,088
Income taxes payable	(666)	346	5,054
Net cash provided by (used in) operating activities	(2,431)	24,008	54,028
Cash flows from investing activities:
Escrow payment received related to Nanda acquisition	0	508	0
Purchase of Nanda's net assets, net of cash received	0	0	(23,912)
Sales of marketable securities	0	3,000	0
Maturities of marketable securities	47,089	8,336	0
Purchases of marketable securities	(49,182)	(58,647)	0
Purchases of property, plant and equipment	(5,689)	(4,990)	(2,755)
Net cash used in investing activities	(7,782)	(51,793)	(26,667)
Cash flows from financing activities:
Payments to Zygo Corporation related to acquisition	(1,004)	(300)	(432)
Repayments of debt obligations	(5,224)	(2,210)	(2,571)
Proceeds from sale of shares under employee stock option plans and purchase plan	4,967	3,913	7,186
Excess tax benefit from equity awards	(53)	910	3,915
Taxes paid on net issuance of stock awards	(1,181)	(618)	(126)
Repurchases of common stock	(5,000)	(8,504)	(4,257)
Net cash provided by (used in) financing activities	(7,495)	(6,809)	3,715
Effect of exchange rate changes on cash and cash equivalents	(442)	(190)	163
Net increase (decrease) in cash and cash equivalents	(18,150)	(34,784)	31,239
Cash and cash equivalents, beginning of period	62,915	97,699	66,460
Cash and cash equivalents, end of period	44,765	62,915	97,699
Supplemental disclosure of cash flow information:
Cash paid for interest	232	522	757
Cash paid for income taxes	$ 313	$ 5,113	$ 11,149