Stock-Based Compensation (Tables)

3 Months Ended

Jun. 30, 2014

Summary of Stock-Based Compensation Expense

The Company accounts for its stock-based compensation at fair value. The following table summarizes stock-based compensation expense by financial statement line item for the three months ended June 30, 2014 and 2013 (in thousands):

	Three months ended June 30,
	2014		2013
Cost of revenues	$	153	$	205
Research and development		479		575
Selling, general and administrative		949		1,355
Total	$	1,581	$	2,135

Schedule of Weighted Average Assumptions used in Black-Scholes Valuation Model for Stock Options Granted

The weighted-average assumptions used in the Black-Scholes valuation model for stock options granted during the three months ended June 30, 2014 and 2013 are as follows:

	Three months ended June 30,
	2014			2013
Expected volatility		85.5	%		74.6	%
Risk-free interest rate		1.9	%		1.7	%
Expected life (years)		5.8			5.9
Dividend yield		None			None