Segment, Customer and Geographical Reporting - Segment Information (Details) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenues	$ 43,701,000	$ 40,681,000
Gross profit	$ 16,074,000	$ 15,236,000
GM %	37.00%	37.00%
Operating expenses	$ 16,062,000	$ 14,892,000
Impairment of long-lived assets	0	182,000
Operating income (loss)	12,000	162,000
Depreciation and amortization	1,420,000	1,257,000
Capital expenditures	893,000	2,317,000
Intangibles, net	627,000	755,000
Goodwill	5,821,000	5,900,000	$ 5,940,000
Total assets	30,827,000	31,532,000
Optics [Member]
Segment Reporting Information [Line Items]
Revenues	23,250,000	23,053,000
Gross profit	$ 7,939,000	$ 7,667,000
GM %	34.00%	33.00%
Operating expenses	$ 7,853,000	$ 7,003,000
Impairment of long-lived assets	0	0
Operating income (loss)	86,000	664,000
Depreciation and amortization	1,165,000	1,006,000
Capital expenditures	716,000	2,033,000
Intangibles, net	307,000	390,000
Goodwill	882,000	961,000
Total assets	20,520,000	22,946,000
Innovation and Development [Member]
Segment Reporting Information [Line Items]
Revenues	20,451,000	17,628,000
Gross profit	$ 8,135,000	$ 7,569,000
GM %	40.00%	43.00%
Operating expenses	$ 8,086,000	$ 7,072,000
Impairment of long-lived assets	0	0
Operating income (loss)	49,000	497,000
Depreciation and amortization	241,000	237,000
Capital expenditures	177,000	211,000
Intangibles, net	128,000	162,000
Goodwill	4,939,000	4,939,000
Total assets	10,112,000	8,376,000
Biomedical [Member]
Segment Reporting Information [Line Items]
Revenues	0	0
Gross profit	$ 0	$ 0
GM %	0.00%	0.00%
Operating expenses	$ 123,000	$ 817,000
Impairment of long-lived assets	0	182,000
Operating income (loss)	(123,000)	(999,000)
Depreciation and amortization	14,000	14,000
Capital expenditures	0	73,000
Intangibles, net	192,000	203,000
Goodwill	0	0
Total assets	$ 195,000	$ 210,000