Submicrometer digital in-line holographic microscopy at 32 nm with high-order harmonics

Abstract

Soft-x-ray digital in-line microscopic holography is achieved using a fully coherent high-order harmonic source emitting at 32 nm. Combination of commercial-grade soft-x-ray optics and a back-illuminated CCD detector allows a compact and versatile holographic setup. Different experimental geometries have been tested by imaging calibrated 50 nm tips and 1 microm wires. Spatial resolution of 800 nm is measured with magnifications ranging from 30 to 110 and a numerical aperture around 0.01. Finally, the potentiality of three-dimensional numerical reconstruction from a single hologram acquisition is shown experimentally.

Two and Three Dimensional Extreme Ultraviolet Holographic Imaging with a Nanometer Spatial Resolution

“…The practical demonstration of EUV and SXR holography proved to be difficult in particular because the lack of sufficiently bright and coherent sources at short wavelengths, and to the fact that coherent EUV and SXR laser sources have historically been restricted to large user facilities. The first demonstration of a coherent table-top holographic imaging achieved 7 µm spatial resolution with a spatially-coherent HHG source (Bartels et al, 2002); this resolution has been extended to a resolution of 0.8 µm in later experiments (Morlens et al, 2006). Time resolved holographic imaging was also implemented with HHG sources to study the ultrafast dynamics of surface deformation with a longitudinal resolution of less than 100 nm and a lateral resolution of less than 80 µm .…”

Iterative Noise Reduction in Digital Holographic Microscopy

“…A conventional setup in DHM is based on the use of an external reference wave (RW), which interferes with the field generated by the object, forming an intensity pattern which is known as hologram of the field (Takeda et al, 1982;Kreis, 1986;Yamaguchi-Zhang, 1997;Yamaguchi et al, 2001;Arrizón-Sanchez, 2004;Liebling, 2004;Quian, 2006;Meneses-Fabian, 2006;Guo, 2007;Cruz et al, 2009). Alternately, it is possible to omit the external RW, with a consequent simplification of the optical setup (Pedrini, 1998;Xu, 2002;Morlens, 2006;Garcia-Sucerquia, 2006;Hwang-Han, 2007;Singh-Asundi, 2009). In any case, either the object hologram or the intensity of the field scattered by object are recorded with an electronic intensity meter, such as a charge-coupled device (CCD).…”

High harmonics generation: Spatial characterisation and applications

“…This development is motivated by the large field of applications as microscopy [1], phase contrast imaging [2] and holography [3,4]. These sources have demonstrated a high brightness [5] and high degree spatial coherence [7].…”