Significant Suppliers and Customers	12 Months Ended
Jun. 30, 2017
Risks and Uncertainties [Abstract]
Significant Suppliers and Customers	16. Significant Suppliers and Customers We utilize a number of glass compositions in manufacturing our molded glass aspheres and lens array products. These glasses or equivalents are available from a large number of suppliers, including CDGM Glass Company Ltd., Ohara Corporation, and Sumita Optical Glass, Inc. Base optical materials, used in both GRADIUM and collimator products, are manufactured and supplied by a number of optical and glass manufacturers. ISP utilizes major infrared material suppliers located around the globe for a broad spectrum of infrared crystal and glass. The Company believes that a satisfactory supply of such production materials will continue to be available at reasonable prices, although there can be no assurance in this regard. In fiscal 2017, sales to three customers comprised an aggregate of approximately 26% of our annual revenue, and 26% of accounts receivable as of June 30, 2017. In fiscal 2016, sales to three customers comprised an aggregate of approximately 25% of our annual revenue, and 25% of accounts receivable as of June 30, 2016. The loss of any of these customers, or a significant reduction in sales to any such customer, would adversely affect our revenues.

Significant Suppliers and Customers

12 Months Ended

Jun. 30, 2017

16. Significant Suppliers and Customers

We utilize a number of glass compositions in manufacturing our molded glass aspheres and lens array products. These glasses or equivalents are available from a large number of suppliers, including CDGM Glass Company Ltd., Ohara Corporation, and Sumita Optical Glass, Inc. Base optical materials, used in both GRADIUM and collimator products, are manufactured and supplied by a number of optical and glass manufacturers. ISP utilizes major infrared material suppliers located around the globe for a broad spectrum of infrared crystal and glass. The Company believes that a satisfactory supply of such production materials will continue to be available at reasonable prices, although there can be no assurance in this regard.

In fiscal 2017, sales to three customers comprised an aggregate of approximately 26% of our annual revenue, and 26% of accounts receivable as of June 30, 2017. In fiscal 2016, sales to three customers comprised an aggregate of approximately 25% of our annual revenue, and 25% of accounts receivable as of June 30, 2016. The loss of any of these customers, or a significant reduction in sales to any such customer, would adversely affect our revenues.