Summary of Significant Accounting Policies (Revenue by Product) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 27,266	$ 17,219	$ 76,598	$ 62,965
Concentration risk percentage	100.00%	100.00%
Navigation And Inertial Sensing [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 9,861	$ 5,604	28,970	12,157
Concentration risk percentage	36.00%	32.00%
Defense Optoelectronics [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 4,164	$ 2,514	11,772	6,974
Concentration risk percentage	16.00%	15.00%
CA TV Lasers And Transmitters [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 10,905	$ 6,849	29,070	32,383
Concentration risk percentage	40.00%	40.00%
Chips [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 1,443	$ 1,854	4,033	9,570
Concentration risk percentage	5.00%	11.00%
Other Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenue	$ 893	$ 398	$ 2,753	$ 1,881
Concentration risk percentage	3.00%	2.00%
Product Concentration Risk | Revenue from Contract with Customer
Disaggregation of Revenue [Line Items]
Concentration risk percentage			100.00%	100.00%
Product Concentration Risk | Revenue from Contract with Customer | Navigation And Inertial Sensing [Member]
Disaggregation of Revenue [Line Items]
Concentration risk percentage			38.00%	19.00%
Product Concentration Risk | Revenue from Contract with Customer | Defense Optoelectronics [Member]
Disaggregation of Revenue [Line Items]
Concentration risk percentage			15.00%	11.00%
Product Concentration Risk | Revenue from Contract with Customer | CA TV Lasers And Transmitters [Member]
Disaggregation of Revenue [Line Items]
Concentration risk percentage			38.00%	52.00%
Product Concentration Risk | Revenue from Contract with Customer | Chips [Member]
Disaggregation of Revenue [Line Items]
Concentration risk percentage			5.00%	15.00%
Product Concentration Risk | Revenue from Contract with Customer | Other Revenue [Member]
Disaggregation of Revenue [Line Items]
Concentration risk percentage			4.00%	3.00%