Improving the resolution of grating-assisted optical diffraction tomography using a priori information in the reconstruction procedure

摘要

We provide a numerical study of a tomographic microscope in which the sample is deposited on a periodically nanostructured substrate and is illuminated under various incident angles. The map of permittivity of the sample is retrieved numerically from the complex data of the diffracted far-field. A single-scattering analysis shows that, with an optimized grating of period λ/5, the transverse resolution of the digital imager is about λ/10. To ameliorate the resolution further, a priori information is incorporated in the inversion procedure. Fixing the lower and upper bounds of the sample permittivity permits us to obtain a transverse resolution about λ/15.