Erlangen 2018 – scientific programme

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A: Fachverband Atomphysik

A 20: Attosecond Science III

A 20.2: Invited Talk

Tuesday, March 6, 2018, 14:30–15:00, K 1.011

Controlling the refraction of ultrashort XUV pulses — Lorenz Drescher, Oleg Kornilov, Tobias Witting, Geert Reitsma, Jochen Mikosch, Marc Vrakking, and •Bernd Schütte — Max-Born-Institut, Berlin

Refraction is widely found in nature and is important for many applications. For instance, refractive lenses and prisms are indispensable tools that are extensively used to control the properties of light beams at visible, infrared and ultraviolet wavelengths. The lack of refractive lenses and prisms in the XUV range is due to the large absorption and the low capability of bending light in this spectral region.

Here we demonstrate control over the refraction of ultrashort XUV pulses by applying a gas density gradient across the XUV beam profile that leads to spectral dispersion and refraction of the beam. The deflection of XUV radiation is particularly large for spectral components close to atomic and molecular resonances, and the experimental results are well reproduced by simulations. Control of the sign and the strength of refraction in different spectral regions is demonstrated by varying the gas pressure, the gas jet position and its composition. The gas jet thereby acts as a deformable prism in the XUV range. We further show temporal control and characterization of the refracted XUV radiation by applying a moderately intense NIR laser pulse.

In the future, our concept may be exploited to measure transient refractive index changes in the XUV region. Furthermore, our results may be the first step towards the design of an XUV refractive lens, which would provide novel opportunities in ultrafast XUV science.