Segment and Revenue Information - Schedule of Revenue by Major Product Category (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue	$ 24,953	$ 42,236
Inertial Navigation | Aerospace And Defense
Disaggregation of Revenue [Line Items]
Total revenue	19,979	8,145
Defense Optoelectronics | Aerospace And Defense
Disaggregation of Revenue [Line Items]
Total revenue	1,696	1,755
CATV Optical Transmitters and Components | Broadband
Disaggregation of Revenue [Line Items]
Total revenue	1,553	28,459
Data Center Chips | Broadband
Disaggregation of Revenue [Line Items]
Total revenue	407	1,068
Optical Sensing | Broadband
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,318	$ 2,809