Year: 2025
Type: article
Abstract: A laser phase plate (LPP), in which a phase shift of unscattered electrons is introduced via interaction of electrons with strong laser fields [1], has been shown to significantly increase contrast in cryo electron microscopy [2]. This new approach has demonstrated the possibility of accurate control of the phase shift value for prolonged periods of time [4]. However, certain properties of a single LPP may require further improvement. Particularly, the presence of ghost images, which are the result of diffraction of the electron beam on the standing laser wave, may deteriorate the image quality and require complicated image processing algorithms for removal. The high laser power required to operate the SLPP also imposes limitations on the quality of the cavity mirrors and leads to thermally induced deformations of the mirrors, further complicating the operation of the optical cavity. It has been demonstrated theoretically that these imperfections can be overcome by combining two LPPs orthogonally to each other [4]. This method not only directly reduces the intensity of the ghost images, but also introduces new acquisition approaches that have the potential of further decreasing the intensity of the ghosts. Moreover, splitting the laser power between two cavities will significantly lower the heating of each mirror in each cavity, improving its stability during operation. In this presentation, we will discuss the progress on the development of a dual LPP (Fig. 1), which has recently been installed in a specially designed TFS Krios G4 transmission electron microscope [5]. A) Schematic representation of the dual laser phase plate. Scale bar, 10 mm. b) Dual laser phase plate. Scale bar, 10 mm.
Source: Microscopy and Microanalysis
Language: English
Subfield: Structural Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W4412910467