High precision wavefront reconstruction technology for single interferogram

Moir fringe, Fourier transform and digital phase shifting techniques are combined together to realize high precision phase calculation and wavefront reconstruction for the single interferogram. First, four digital phase shifting fringes, which the frequency is similar with the original fringe tested, were generated by computer, and phase shifting Moir fringesare formed by superposition of original and digital fringes. Then, the phase of original interferogram was obtained through Fourier transform, double frequency filtering, inverse Fourier transform and phase shift technology. Finally, the wavefront shape related original interferogram was reconstructed by wavefront fitting. The experimental result shows that this technology not only removes both of nonlinear error from traditional hardware phase shifting and spectral shift error, and get wavefront with high precision for single interferogram, but also simplifies the mechanical structure of system. At the same time, it reduces the demands on the environment, so it is very much suitable to use in work shop.