Measurement of conformal windows with IR-FORM: InfraRed Flexible Optical Ray Metrology
Navy SBIR FY2015.2

Sol No.: Navy SBIR FY2015.2
Topic No.: N152-105
Topic Title: Measurement of conformal windows with IR-FORM: InfraRed Flexible Optical Ray Metrology
Proposal No.: N152-105-0532
Firm: Arizona Optical Systems, LLC
5575 S. Houghton Rd.
Tucson, Arizona 85747
Contact: James Burge
Phone: (520) 334-5937
Abstract: Arizona Optical Systems has developed the breakthrough technology FORM (Flexible Optical Ray Metrology) that measures complex aspheric windows in transmission, providing surface maps of both sides of the window. The FORM measurement system for window metrology uses a custom sensor package that looks through the window at modulated images on a digital display. Powerful tomographic software and careful calibration are used to determine the surface irregularity of both surfaces of the window. Having performed the key demonstration of the FORM technique, we now propose to develop an infrared version of this test, capable of measuring visibly opaque windows that do not transmit visible wavelength light. This system uses thermal radiation from a modulated infrared source detected by a thermal imaging sensor assembly. In Phase I we will perform the key technology demonstration that shows feasibility for this new IR-FORM technique. In Phase II, we will incorporate the IR-FORM technology into a measurement system and use it to measure visibly opaque windows and domes.
Benefits: In response to the need outlined in this solicitation, Arizona Optical Systems has already advanced the field of deflectometry and successfully demonstrated FORM technology, which uses a proprietary sensor package looking through the window at sinusoidal intensity variations from a digital display. The system provides a highly accurate measurement of a three-dimensional ray trace through the window. AOS software calculates a tomographic solution to determine the surface irregularity on both sides of the window. The technology to date requires the use of the digital display, which limits the system to visible light applications. By incorporating the AOS modulated infrared source, AOS extends the technology into the infrared. We propose to develop the technology for measuring transmitted wavefront with infrared radiation from a modulated infrared source. We will combine this with the FORM technology to provide measurements of both surfaces of visibly opaque windows. We will demonstrate this technology by measuring a hot-pressed MgF2 window and dome. The significance of this technology is clear. The FORM technique has the dynamic range to accurately measure a wide range of sizes and curvature of freeform aspheric windows. The IR-FORM development extends this technique to measuring virtually any window that may be desired. The measurement capability can be used to provide data for computer controlled polishing of window surfaces, which allows the complete manufacture of a class of window that is currently unavailable.