The Company has stock-based compensation plans under which it grants stock options, restricted stock awards, restricted stock units and deferred stock units. Stock-based compensation expense was reported as follows on the consolidated statements of operations:


	Fiscal Year
(In thousands)	2022		2021		2020
Product costs	$	234	$	122	$	119
Research and development		1,424		1,298		896
Selling, general and administrative		5,399		4,443		4,438
Total stock-based compensation expense	$	7,057	$	5,863	$	5,453

As of September 30, 2022, approximately $10.5 million of total unrecognized compensation costs related to non-vested awards is expected to be recognized over a weighted average period of approximately 2.3 years.

Under the amended 2019 Equity Incentive Plan (“2019 Plan”), the Company is authorized to issue 1,900,000 shares, plus the number of shares pursuant to any awards granted under the 2009 Equity Incentive Plan (“2009 Plan”) that were outstanding on the effective date of the 2019 Plan that expire, are cancelled or forfeited, or are settled for cash. As of September 30, 2022, there were approximately 845,000 shares available for future equity awards under the 2019 Plan, including stock options, restricted stock, restricted stock units and deferred stock units.

The Company grants non-qualified stock options at fair market value on the grant date to certain key employees and members of the Board. The Company uses the Black-Scholes option pricing model to determine the fair value of stock options as of the date of each grant. Weighted average stock option fair value assumptions and the weighted average grant date fair value of stock options granted were as follows:


	Fiscal Year
	2022			2021			2020
Stock option fair value assumptions:
Risk-free interest rate		1.49	%		0.40	%		1.41	%
Expected life (years)	4.6			4.6			4.6
Expected volatility		43	%		43	%		39	%
Dividend yield		—	%		—	%		—	%
Weighted average grant date fair value of stock options granted	$	15.96		$	14.71		$	14.13

The risk-free interest rate assumption is based on the U.S. Treasury’s rates for U.S. Treasury zero-coupon bonds with maturities similar to those of the expected term of the awards. The expected life of options granted is determined based on the Company’s experience. Expected volatility is based on the Company’s stock price movement over a period approximating the expected term. Based on management’s judgment, dividend yields are expected to be zero for the expected life of the options.

With respect to members of the Board, non-qualified stock options generally become exercisable on a monthly pro-rata basis within the one-year period following the date of grant. With respect to employees, non-qualified stock options generally become exercisable at a 25% rate on each of the first four anniversaries following the grant date. Non-qualified stock options generally expire in seven years or upon, or shortly after termination of employment or service as a Board member. The stock-based compensation expense table above includes stock option expenses recognized related to these awards, which totaled $3.4 million, $2.8 million and $2.5 million in fiscal 2022, 2021 and 2020, respectively.

As of September 30, 2022, the aggregate intrinsic value of the option shares outstanding was $0.6 million, and the aggregate intrinsic value of option shares exercisable was $0.6 million. As of September 30, 2022, the weighted average remaining contractual life of options outstanding and options exercisable was 4.5 years and 3.2 years, respectively. The total pre-tax intrinsic value of options exercised was $1.0 million, $7.1 million and $2.0 million in fiscal 2022, 2021 and 2020, respectively. The intrinsic value represents the difference between the exercise price and the fair market value of the Company’s common stock on the last day of the respective fiscal year end.

Stock option activity was as follows:


(In thousands, except per share data)	Number of Shares			Weighted Average Exercise Price
Options outstanding at September 30, 2019		871		$	32.18
Granted		299			41.06
Exercised		(125	)		22.89
Forfeited and expired		(105	)		41.69
Options outstanding at September 30, 2020		940			35.18
Granted		274			40.95
Exercised		(248	)		24.22
Forfeited and expired		(44	)		44.58
Options outstanding at September 30, 2021		922			39.39
Granted		342			42.10
Exercised		(45	)		21.24
Forfeited and expired		(58	)		43.99
Options outstanding at September 30, 2022		1,161			40.66
Options vested and exercisable at September 30, 2022		546		$	39.44

The Company has entered into restricted stock agreements with certain key employees, covering the issuance of common stock (“Restricted Stock”). Restricted Stock generally vests at a 33% rate on each of the first three anniversaries following the grant date. Restricted Stock is released to employees if they are employed by the Company at the end of the vesting period. Restricted Stock is valued based on the market value of the shares as of the date of grant with the value allocated to expense evenly over the vesting period. The stock-based compensation expense table above includes Restricted Stock expenses recognized related to these awards, which totaled $2.7 million, $2.2 million and $2.0 million in fiscal 2022, 2021 and 2020, respectively.

Restricted Stock activity was as follows:


(In thousands, except per share data)	Number of Shares			Weighted Average Grant Date Fair Value
Unvested restricted stock awards at September 30, 2019		90		$	43.69
Granted		67			41.40
Vested		(43	)		38.74
Forfeited		(14	)		44.76
Unvested restricted stock awards at September 30, 2020		100			44.16
Granted		71			38.83
Vested		(48	)		44.07
Forfeited		(4	)		40.45
Unvested restricted stock awards at September 30, 2021		119			41.14
Granted		99			42.35
Vested		(55	)		42.98
Forfeited		(5	)		41.83
Unvested restricted stock awards at September 30, 2022		158		$	41.24

The Company has entered into restricted stock unit agreements with certain key employees in foreign jurisdictions and members of the Board, covering the issuance of common stock (“RSUs”). With respect to employees, RSUs generally vest at a 33% rate on each of the first three anniversaries following the grant date, and RSUs are settled in shares and issued to the employees if they are employed by the Company at the end of the vesting period. With respect to members of the Board, RSUs vest on a monthly pro-rata basis within the one-year period following the date of grant, and RSUs are settled in shares and generally issued upon termination of service as a Board member. RSUs are valued based on the market value of the shares as of the date of grant with the value allocated to expense evenly over the vesting period. The Company awarded approximately 14,000, 17,000 and 18,000 RSUs in fiscal 2022, 2021 and 2020, respectively. As of September 30, 2022 and 2021, outstanding RSUs (including unvested units and vested units not yet settled) totaled approximately 65,000 and 61,000 units, respectively, with a weighted average grant date fair value per unit of $33.14 and $33.45, respectively. The stock-based compensation table above includes RSU expenses recognized related to these awards, which totaled $0.5 million, $0.5 million and $0.6 million in fiscal 2022, 2021 and 2020, respectively.

Directors may elect to receive their annual fees for services to the Board in deferred stock units (“DSUs”). DSUs are fully vested and expensed upon grant at the market value of the shares on the grant date. DSUs are settled in shares and issued to the Director upon termination of service as a Board member. As of September 30, 2022 and 2021, outstanding, fully vested DSUs totaled approximately 36,000 and 34,000 units, respectively, with a weighted average grant date fair value per unit of $30.97 and $30.32, respectively. The stock-based compensation expense table above includes DSU expenses recognized related to these awards, which totaled $0.1 million per year in each of fiscal 2022, 2021 and 2020.

Under the amended 1999 Employee Stock Purchase Plan (“ESPP”), the Company is authorized to issue up to 600,000 shares of common stock. All full-time and part-time U.S. employees can elect to have up to 10% of their annual compensation withheld, with an annual limit of $25,000, to purchase the Company’s common stock at purchase prices defined within the provisions of the ESPP. ESPP share awards are valued based on the value of the discount feature plus the fair value of the optional features as of the date of grant using the Black-Scholes valuation model. The value of these share awards is allocated to expense evenly over each six-month purchase period. Employee contributions to the ESPP included in accrued liabilities on the consolidated balance sheets totaled $0.1 million as of both September 30, 2022 and 2021. The stock-based compensation expense table above includes expenses recognized related to the ESPP, which totaled $0.3 million, $0.2 million and $0.2 million for fiscal 2022, 2021 and 2020, respectively.