NOTE 5-STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION EXPENSE

Share-based Compensation Plans

The Company has a share-based compensation program, most recently, the 2000 Amended and Restated Equity Incentive Plan (the "Plan"), that provides the Board of Directors broad discretion in creating equity incentives for employees, officers, directors and consultants. This program includes incentive and non-qualified stock options and non-vested stock awards (also known as restricted stock) granted under various stock plans. As of June 30, 2012, the Company had approximately 7.4 million shares of common stock reserved for future issuance under its share-based compensation plans including 2.0 million shares of common stock authorized for issuance under out 2012 Inducement Plan that was adopted by the Board of Directors in June 2012. New shares are issued as a result of stock option exercises, restricted stock units vesting and restricted stock award grants.

The Company recognized share-based compensation expense as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2012		2011		2012		2011
Costs of sales	$	340	$	282	$	712	$	573
Research and development		306		511		673		1,038
Selling, general and administrative		9,560		1,013		11,213		2,763
Total share-based compensation expense	$	10,206	$	1,806	$	12,598	$	4,374

Included in selling, general and administrative share-based compensation expense for the three and six months ended June 30, 2012 was $8.3 million related to the acceleration of unvested stock options in connection with the Acquisition.

As of June 30, 2012, $11.5 million of total unrecognized share-based compensation expense related to non-vested awards is expected to be recognized over the respective vesting terms of each award through 2016. The weighted‑average term of the unrecognized share-based compensation expense is 2.6 years.

Stock Options

The fair value of options was estimated at the date of grant using the Black Scholes Merton option pricing model with the following weighted‑average assumptions:

	Three Months Ended June 30,						Six Months Ended June 30,
	2012			2011			2012			2011
Risk free interest rate		0.7	%		1.8	%		0.8	%		2.2	%
Expected dividend yield		0.0	%		0.0	%		0.0	%		0.0	%
Expected volatility		67	%		67	%		67	%		67	%
Expected option term (in years)		4.6			4.5			4.6			4.5

The risk free interest rate for periods within the contractual life of the Company's stock options is based on the U.S. Treasury yield curve in effect at the time of grant. The expected term is derived from an analysis of the Company's historical exercise trends over ten years. The expected volatility for the three and six months ended June 30, 2012 and 2011 is based on a blend of historical and market‑based implied volatility. Using the assumptions above, the weighted‑average grant date fair value of options granted during the three months ended June 30, 2012 and 2011, was $2.55 and $3.16, respectively, and during the six months ended June 30, 2012 and 2011, was $2.48 and $2.91, respectively.

Performance-Based Awards

In 2011, the Compensation Committee of the Company's Board of Directors approved a grant of performance-based restricted stock units ("PRSUs") under the Plan to an executive officer that is earned annually in four equal tranches (the "Performance Period"). The PRSUs entitle the executive to receive a certain number of shares of the Company's common stock based on the Company's satisfaction of certain financial and strategic performance goals as set and approved by the Board of Directors annually during the first quarter of the specific performance period. Based on the achievement of the performance conditions during each Performance Period, the final settlement of the PRSU award will vest twelve months following the end of each Performance Period. The PRSU award will be forfeited if the performance goals are not met or if the executive officer is no longer employed at the vest date.

The number of shares underlying the PRSUs that were granted to the executive officer during 2011 totaled 240,000 shares. As of June 30, 2012, performance conditions pertaining to 60,000 shares of the PRSUs, with a grant date fair value of $6.71 per PRSU, were achieved and the fair value of the vested PRSU's is being amortized on a straight-line basis over the remaining service period. The Company expects that an additional 30,000 shares of the PRSUs, with a grant date fair value of $4.63 per PRSU, will vest and the fair value of such PRSU's is being amortized on a straight-line basis over the related service period. The total compensation cost related to PRSUs granted but not yet recognized was approximately $0.2 million as of June 30, 2012.

Employee Stock Purchase Plan

In August 2011, the Company's Board of Directors adopted the 2011 Employee Stock Purchase Plan ("ESPP") that was approved by the Company's stockholders on May 11, 2012. The ESPP reserved a total of 7.0 million shares of the Company's common stock for issuance under the plan and permits eligible employees to purchase common stock at a discount through payroll deductions.

The price at which stock is purchased under the ESPP is equal to 85% of the fair market value of the common stock on the first day of the offering period or the last day of the purchase period, whichever is lower. The offering periods are twelve months and include two six month purchase periods that result in a look-back for determining the purchase price of up to 12 months. Employees can invest up to 15% of their gross compensation through payroll deductions. In no event would an employee be permitted to purchase more than 750 shares of common stock during any six-month purchase period. The initial offering period commenced in November 2011. As of June 30, 2012, there were 295 participants in the plan and approximately 133,051 shares were issued under the ESPP during the period at a subscription date fair value of $4.23 per share. Included in total share-based compensation cost for the three and six months ended June 30, 2012 was $0.1 million and $0.3 million, respectively, related to the ESPP.

During the three and six months ended June 30, 2012, the fair value of shares under the ESPP was estimated using the following assumptions:

Risk free interest rate		0.1%
Expected dividend yield		0.0%
Expected volatility		67%
Expected term (in years)		0.8