分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Light-matter interaction is exploited in spectroscopic techniques to access information about molecular, atomic or nuclear constituents of the sample of interest. While scattered light carries both amplitude and phase information of the electromagnetic field, most of the time the latter is lost in intensity measurements. However, often the phase information is paramount to reconstruct the desired information of the target, as it is well known from coherent x-ray imaging. Here we introduce a new phase retrieval algorithm which allows us to reconstruct the field phase information from two-dimensional time- and energy-resolved spectra. We apply this method to the particular case of x-ray scattering off M\"ossbauer nuclei at a synchrotron radiation source. Knowledge of the phase allows also for an excellent reconstruction of the energy spectra from experimental data, which could not be achieved with this resolution otherwise. Our approach provides an efficient novel data analysis tool which will benefit x-ray quantum optics and M\"ossbauer spectroscopy with synchrotron radiation alike.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: By restricting the spatial energy transmission of an electromagnetic wave, dielectric waveguides transmit light over long distances at sustained intensity. Waveguides have been used in the microwave and optical range to maintain strong signal intensities in connection with lasers, but guiding of intense short-wavelength radiation such as x-rays has proven more cumbersome. Here we investigate theoretically how tapered x-ray waveguides can focus and guide radiation from x-ray free electron lasers. Elliptical waveguides using a cladding material with high atomic number such as platinum can maintain an x-ray intensity up to three orders of magnitude larger than in free space. This feature can be used to significantly enhance resonant interactions of x-rays, for instance driving nuclear transitions up to transient nuclear population inversion. This could be the first breakthrough in nuclear state population control. Our results anticipate the important role of tapered x-ray waveguides in the emerging field of x-ray quantum optics with nuclear transitions.