Compact soft x-ray transmission microscopy with sub-50 nm spatial resolution

Abstract

In this paper, the development of compact transmission soft x-ray microscopy (XM) with sub-50 nm spatial resolution for biomedical applications is described. The compact transmission soft x-ray microscope operates at lambda = 2.88 nm (430 eV) and is based on a tabletop regenerative x-ray source in combination with a tandem ellipsoidal condenser mirror for sample illumination, an objective micro zone plate and a thinned back-illuminated charge coupled device to record an x-ray image. The new, compact x-ray microscope system requires the fabrication of proper x-ray optical devices in order to obtain high-quality images. For an application-oriented microscope, the alignment procedure is fully automated via computer control through a graphic user interface. In imaging studies using our compact XM system, a gold mesh image was obtained with 45 nm resolution at x580 magnification and 1 min exposure. Images of a biological sample (Coscinodiscus oculoides) were recorded.

Water-window microscopy using a compact, laser-plasma SXR source based on a double-stream gas-puff target

“…A quasimonochromatic emission from a laser-plasma EUV source based on a gas puff target [8] allowed for sub-70 nm spatial resolution imaging [9,10] in a very compact system. A quasi-monochromatic emission from an incoherent SXR source, at much shorter wavelength, k = 2.88 nm, in the ''water-window'' spectral range, based on the liquid nitrogen, allowed to demonstrate SXR microscopy with a sub-50 nm spatial resolution [11]. Ethanol droplet-based SXR source at k = 3.37 nm, combined with a zone plate objective allowed to capture images with spatial resolution of 60 nm [12], later improved to *50 nm [13].…”

Nanoimaging using soft X-ray and EUV laser-plasma sources

“…The synchrotron radiation at λ = 2.4 nm was used for imaging frozenhydrated samples at atmospheric pressure [4] to observe internal details of algae cells with a spatial resolution of ~35 nm. A SXR source, emitting at λ = 2.88 nm, based on a liquid jet nitrogen target was employed recently for microscopy in the "water-window" range with a sub-50 nm spatial resolution, but this system present a very complicated hardware [5]. A compact high order harmonic generation (HHG) source was employed for sub-100 nm spatial resolution imaging [6].…”

Bioimaging Using Full Field and Contact EUV and SXR Microscopes with Nanometer Spatial Resolution

“…An SXR source, emitting at λ = 2.88 nm, based on a liquid jet nitrogen target, was employed recently for microscopy in the 'water-window' range with a sub-50 nm spatial resolution, but this system presents very complicated hardware [15]. Another nano-imaging technique is represented by the employment of compact high order harmonic generation (HHG) sources for sub-100 nm spatial resolution [16,17].…”