单幅干涉条纹图的高精度波面重建技术

结合莫尔条纹、傅里叶变换和数字相移技术实现了对单幅干涉条纹图的高精度相位计算和波面重建.首先,用计算机生成与被处理干涉条纹频率相近的数字相移条纹图,与实际干涉条纹图叠加得到相移莫尔条纹图;然后,利用傅里叶变换、双频滤波、傅里叶反变换和相移技术得到干涉条纹图的相位数据;最后利用波面拟合技术重构原干涉条纹图对应的波面形状.研究结果表明,该技术不仅消除了干涉仪硬件相移产生的非线性误差和滤波时的频谱移中误差,高精度获得了单幅干涉条纹图对应的波前,而且简化了系统的机械结构.同时,对环境的要求明显降低,特别适用于生产现场的检测.

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.