Broadband coherent diffractive imaging

Abstract

Recent technological advances in attosecond science hold the promise of tracking electronic processes at the shortest space and time scales. However, the necessary imaging methods combining attosecond temporal resolution with nanometre spatial resolution are currently lacking. Regular coherent diffractive imaging, based on the diffraction of quasi-monochromatic illumination by a sample, is inherently incompatible with the extremely broad nature of attosecond spectra. Here, we present an approach that enables coherent diffractive imaging using broadband illumination. The method is based on a numerical monochromatization of the broadband diffraction pattern by the regularized inversion of a matrix that depends only on the spectrum of the diffracted radiation. Experimental validations using visible and hard X-ray radiation show the applicability of the method. Because of its generality and ease of implementation we expect this method to find widespread applications such as in petahertz electronics or attosecond nanomagnetism. Coherent diffractive imaging using broadband illumination is demonstrated at visible and X-ray wavelengths. The method is based on a numerical monochromatization of the broadband diffraction pattern by the regularized inversion of a matrix.