Intangible Assets (Schedule by Reporting Segment) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Sep. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Assets	$ 22,463	$ 22,907
Accumulated Amortization	(21,067)	(20,748)
Other intangible assets, net	1,396	2,159
Estimated Future Amortization Expense
Three months ended September 30, 2014	255
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
Other intangible assets, net	1,396	2,159
Fiber Optics
Finite-Lived Intangible Assets [Line Items]
Gross Assets	20,935	20,935
Accumulated Amortization	(19,587)	(18,967)
Other intangible assets, net	1,348	1,968
Estimated Future Amortization Expense
Other intangible assets, net	1,348	1,968
Fiber Optics | Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross Assets	12,727	12,727
Accumulated Amortization	(12,138)	(11,822)
Other intangible assets, net	589	905
Estimated Future Amortization Expense
Other intangible assets, net	589	905
Fiber Optics | Customer Relations
Finite-Lived Intangible Assets [Line Items]
Gross Assets	3,511	3,511
Accumulated Amortization	(2,863)	(2,647)
Other intangible assets, net	648	864
Estimated Future Amortization Expense
Other intangible assets, net	648	864
Fiber Optics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	4,697	4,697
Accumulated Amortization	(4,586)	(4,498)
Other intangible assets, net	111	199
Estimated Future Amortization Expense
Other intangible assets, net	111	199
Photovoltaics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	1,528	1,972
Accumulated Amortization	(1,480)	(1,781)
Other intangible assets, net	48	191
Estimated Future Amortization Expense
Other intangible assets, net	$ 48	$ 191