A new full aperture wavefront measuring method for conformal domes

Conformal windows technology is widely applied to meet the aerodynamics and optical performance requirements. The conformal optical domes have high steepness and high precision shapes. Thus it is necessary to improve the interferometric method to measure the form qualities of conformal domes precisely and effectively. In this paper we introduce a novel full aperture measuring method to test the transmission wavefront of the dome surface. An aspheric compensator is designed and placed behind the dome to reflect the aspheric testing wave back to the same path. It is practical to assemble the testing system with high precision for its simple structure. In addition, tolerance analysis is conducted, and the accuracy of this method is verified to be λ/30 (λ=3.39um). The influence of different error factors, including the thickness error and decenter error, on the testing wavefront is analyzed, and then guidance to assembly is given accordingly.