Stock-based Compensation Plans (Tables)

12 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-based Compensation Expenses

Stock-based compensation expense was reported as follows on the consolidated statements of operations:

	Fiscal Year
(In thousands)	2023		2022		2021
Product costs	$	279	$	234	$	122
Research and development		1,417		1,424		1,298
Selling, general and administrative		5,909		5,399		4,443
Total stock-based compensation expense	$	7,605	$	7,057	$	5,863

Stock Option Fair Value Assumptions and Weighted Average Grant Date Fair Value of Stock Options Granted

stock option fair value assumptions and the weighted average grant date fair value of stock options granted were as follows:

	Fiscal Year
	2023			2022			2021
Stock option fair value assumptions:
Risk-free interest rate		3.76	%		1.49	%		0.40	%
Expected life (years)	4.7			4.6			4.6
Expected volatility		45	%		43	%		43	%
Dividend yield		—	%		—	%		—	%
Weighted average grant date fair value of stock options granted	$	15.03		$	15.96		$	14.71

Schedule of Stock Option Activity

Stock option activity was as follows:

(In thousands, except per share data)	Number of Shares			Weighted Average Exercise Price
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
Granted		311			34.73
Exercised		(20	)		21.50
Forfeited and expired		(90	)		41.77
Options outstanding at September 30, 2023		1,362			39.52
Options vested and exercisable at September 30, 2023		724		$	40.47

Schedule of Restricted Stock Activity

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, 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
Granted		103			35.75
Vested		(69	)		40.96
Forfeited		(19	)		39.31
Unvested restricted stock awards at September 30, 2023		173		$	38.30