Stitching Absolute Distance Inteferometer

The Navy is seeking to develop an advanced and precise method of measuring the optical figure of deep concave optics, including an ogive dome, to be demonstrated on a polycrystalline alumina dome to be provided by the Government. To meet this need, Physical Optics Corporation (POC) proposes to develop a new Stitching Absolute Distance Interferometer (SADI). SADI will operate in several laser wavelengths in the MWIR spectrum. This combination of wavelengths will provide data for absolute distance interferometry. Thus, the interferometer will obtain the thickness of the dome from the transmitted wavefront test. The stitching of the patches provides comprehensive information for dome repolishing to achieve designed transmitted waveform conditions. The SADI will be a flexible and inexpensive universal solution for the testing of conformal domes. While the typical accuracy of an interferometric test is 0.002-0.005 times the synthetic wavelength peak-to-valley of wavefront deformation, the SADI’s accuracy will be about 0.05 of this wave, which meets Navy requirements. In Phase I, POC will design and assemble a bench prototype SADI and will prove the feasibility of the concept. In Phase II, an optimized prototype SADI will be fabricated and tested.BENEFITS: The proposed technology has a broad spectrum of application in optical shops and service facilities to control optical elements with complex conformal shapes for military equipment, scientific devices, and commercial systems. Its primary military and civil applications will be in conformal optics testing and various aerodynamic tube turbulence flow tests.