Depth of field in phase-contrast transmission electron microscopy
Year: 2026
Type: article
Abstract: The depth of field (DoF) is an important parameter in transmission electron microscopy (TEM) when considering inhomogeneous samples, tomographic schemes, or in-situ experiments. A large DoF enhances the robustness of the experiment against tight alignment demands and drift issues. The phase-contrast transfer in TEM is reviewed and updated with special regard to the correct derivation and quantification of the DoF for relevant single-transfer-band imaging like with Scherzer or Lentzen conditions. Consequences towards the optimisation of the imaging conditions are discussed. Additionally, the defocus-dependent information limit is treated as a different type of DoF. One result of this work is to prefer the original Scherzer defocus over the Scherzer defocus taught today if a large DoF matters in non-aberration-corrected instruments. In aberration-corrected instruments, the Lentzen conditions are well suited for a maximum DoF if one adapts the desired maximum spatial frequency accordingly, and higher-order spherical-aberration correction might help at lower electron acceleration voltages. • The phase-contrast transfer in TEM is revisited with respect to the depth of field. • The textbook depth of field is supplemented with a correction for minimum contrast transfer. • The same textbook depth of field is rejected for being not meaningful in the realm of phase-contrast transfer. • A meaningful frequency-band depth of field is proposed and quantified. • Optimum imaging conditions for maximum depth of field are evaluated.
Source: Micron
Author: Felix Börrnert
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,440
OpenAlex ID: W7128915145