Effective phase correction function for high-resolution exit wave reconstruction by a three-dimensional Fourier filtering method.

摘要: Abstract The phase correction function used in the three-dimensional Fourier filtering method (3D-FFM) for compensating lens aberrations was investigated to reconstruct a high-resolution exit wave of sample. An appropriate function, which hardly suffered from imperfect illumination conditions, determined by comparing two types functions with numerical calculations and experiments using through-focus images an amorphous thin film [1 1 0]-oriented Si single crystal taken under tilted or partially coherent illumination. Theoretical indicated that terms w (an axial component), available uniquely 3D space, compensated shift due spherical aberration more precisely than did conventional g (the two-dimensional (2D) planar components). Experimentally, waves reconstructed -function showed sample structures at ∼20% higher resolution those -function. Image contrast simulations proved had significant advantage over -function: former canceled out effect divergence, resulting wave. These results demonstrated waves, are realized 3D-FFM, should be -type function.