Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 158,444	$ 110,128	$ 87,265
Cost of revenue	96,956	74,546	72,176
Gross profit	61,488	35,582	15,089
Operating expense:
Selling, general, and administrative	24,544	24,631	32,080
Research and development	17,448	20,269	19,443
Loss (gain) on sale of assets	515	(2,284)	(302)
Total operating expense	42,507	42,616	51,221
Operating income (loss)	18,981	(7,034)	(36,132)
Other income:
Gain on extinguishment of debt	6,561	0	0
Interest income (expense), net	466	(104)	629
Foreign exchange gain (loss)	207	198	(427)
Total other income	7,234	94	202
Income (loss) before income tax expense	26,215	(6,940)	(35,930)
Income tax expense	(572)	(60)	(54)
Net income (loss)	25,643	(7,000)	(35,984)
Foreign exchange translation adjustment	(231)	(32)	65
Comprehensive income (loss)	$ 25,412	$ (7,032)	$ (35,919)
Per share data:
Net income (loss) income per basic share (in dollars per share)	$ 0.75	$ (0.24)	$ (1.29)
Weighted-average number of basic shares outstanding (in shares)	34,020	29,136	27,983
Net income (loss) per diluted share (in dollars per share)	$ 0.72	$ (0.24)	$ (1.29)
Weighted-average number of diluted shares outstanding (in shares)	35,789	29,136	27,983