Kumagai Toshiki, Hibino Kenichi, Tomita Keita, Wasaki Katsumi
Appl Opt. 2022 Oct 20;61(30):8926-8935. doi: 10.1364/AO.465761.
In Fizeau interferometry for high-numerical-aperture spherical surface tests, the mechanical phase shift becomes spatially nonuniform within the observation aperture. We divided the aperture into annular regions and calculated the object phase using several algorithms designed for different phase shifts. The division substantially decreased the nonuniformity; however, it caused bias errors at the regional boundaries in the measured phase. The error is due to the different error coefficients of the algorithms for the phase-shift nonlinearity. A convolution technique that modifies a sampling window to align the error coefficients of a set of algorithms is proposed. The technique is experimentally shown to minimize phase measurement errors.
在用于高数值孔径球面测试的斐索干涉测量中，机械相移在观测孔径内会在空间上变得不均匀。我们将孔径划分为环形区域，并使用针对不同相移设计的几种算法来计算物体相位。这种划分显著降低了不均匀性；然而，它在测量相位的区域边界处引起了偏差误差。该误差是由于相移非线性算法的误差系数不同所致。提出了一种卷积技术，该技术通过修改采样窗口来使一组算法的误差系数对齐。实验表明，该技术可将相位测量误差降至最低。
