Intangible Assets (Schedule by Reporting Segment) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Sep. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Assets	$ 22,907	$ 22,907
Accumulated Amortization	(21,257)	(20,748)
Total	1,650	2,159
Estimated Future Amortization Expense
Six months ended September 30, 2014	509
Fiscal year ended September 30, 2015	555
Fiscal year ended September 30, 2016	554
Fiscal year ended September 30, 2017	32
Fiscal year ended September 30, 2018 and thereafter	0
Total	1,650	2,159
Fiber Optics
Finite-Lived Intangible Assets [Line Items]
Gross Assets	20,935	20,935
Accumulated Amortization	(19,381)	(18,967)
Total	1,554	1,968
Estimated Future Amortization Expense
Total	1,554	1,968
Fiber Optics | Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross Assets	12,727	12,727
Accumulated Amortization	(12,033)	(11,822)
Total	694	905
Estimated Future Amortization Expense
Total	694	905
Fiber Optics | Customer Relations
Finite-Lived Intangible Assets [Line Items]
Gross Assets	3,511	3,511
Accumulated Amortization	(2,791)	(2,647)
Total	720	864
Estimated Future Amortization Expense
Total	720	864
Fiber Optics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	4,697	4,697
Accumulated Amortization	(4,557)	(4,498)
Total	140	199
Estimated Future Amortization Expense
Total	140	199
Photovoltaics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	1,972	1,972
Accumulated Amortization	(1,876)	(1,781)
Total	96	191
Estimated Future Amortization Expense
Total	$ 96	$ 191