# The Rytov Approximation in Electron Scattering

## TL;DR

This paper introduces the Rytov approximation for high-energy electron scattering to improve linear models used in tomography, addressing limitations of conventional models like the Phase Grating Approximation.

## Contribution

It extends the Rytov approximation's application from light microscopy to electron microscopy, enhancing modeling accuracy in strong-scattering regimes.

## Key findings

- Rytov approximation provides reasonable results in electron microscopy.
- Incorporates propagation effects missing in traditional models.
- Potential to improve 3D atomic resolution in electron tomography.

## Abstract

In this work we introduce the Rytov approximation in the scope of high-energy electron scattering with the motivation of developing better linear models for electron scattering. Such linear models play an important role in tomography and similar reconstruction techniques. Conventional linear models, such as the Phase Grating Approximation, have reached their limits in current and forsee- able applications, most importantly in achieving three-dimensional atomic resolution using electron holographic tomography. The Rytov approximation incorporates propagation effects which are the most pressing limitation of conventional models. While predominately used in the weak-scattering regime of light microscopy we show that the Rytov approximation can give reasonable results in the inherently strong-scattering regime of transmission electron microscopy.