Table-Top Milliwatt-Class Extreme Ultraviolet High Harmonic Light Source

Extreme ultraviolet (XUV) lasers are essential for the investigation of fundamental physics. Especially high repetition rate, high photon flux sources are of major interest for reducing acquisition times and improving signal to noise ratios in a plethora of applications. Here, an XUV source based on cascaded frequency conversion is presented, which delivers due to the drastic better single atom response for short wavelength drivers, an average output power of (832 +- 204) {\mu}W at 21.7 eV. This is the highest average power produced by any HHG source in this spectral range surpassing precious demonstrations by more than a factor of four. Furthermore, a narrow-band harmonic at 26.6 eV with a relative energy bandwidth of only {\Delta}E/E= 1.8 x 10E-3 has been generated, which is of high interest for high precision spectroscopy experiments.Comment: 4 Pages, 4 Picture

Annular beam driven high harmonic generation for high flux coherent XUV and soft X-ray radiation

Separation of the high average power driving laser beam from the generated XUV to soft-X-ray radiation poses great challenges in collinear HHG setups due to the losses and the limited power handling capabilities of the typically used separating optics. This paper demonstrates the potential of driving HHG with annular beams, which allow for a straightforward and power scalable separation via a simple pinhole, resulting in a measured driving laser suppression of 5⋅10−3. The approach is characterized by an enormous flexibility as it can be applied to a broad range of input parameters and generated photon energies. Phase matching aspects are analyzed in detail and an HHG conversion efficiency that is only 27% lower than using a Gaussian beam under identical conditions is demonstrated, revealing the viability of the annular beam approach for high flux coherent short-wavelength sources and high average power driving lasers

A Compact Tunable Narrow-Bandwidth and High-Photon-Flux Turnkey XUV Source for Experiments with Highly Charged Ions at Storage Rings

The development of table-top extreme ultraviolet (XUV) light sources has paved the way to a vast variety of applications. Achievable XUV-photon fluxes of lab scale high-harmonic XUV setups can reach up to those typically present at synchrotron sources and free-electron lasers (FELs) [1]. Thus, a variety of experiments comes into reach that was formerly tied to these large scale facilities. The combination of the table-top type XUV sources combined with heavy ion storage rings enables manifold fundamental studies and experiments on core level transitions, highly excited states, or transitions in highly-charged ions [2]

Separation of high average power driving lasers from higher order harmonics using an annular beam

Annular beams are applied as an effective separation method for HHG with high average power driving lasers, showing a comparable conversion efficiency to HHG with a Gaussian beam

Narrowband high harmonic source with multi-mW average power based on cascaded frequency conversion

We report on efficient high harmonic generation based on cascaded frequency conversion of a high power femtosecond fiber laser. Using krypton as generation medium, up to 2.8 mW (8·1014 photons/s) of average power have been generated within a single narrowband harmonic at 21.6 eV. Furthermore, a strong window-resonance in argon has been utilized to achieve relative energy bandwidths of ΔE/E=3·10−3 at 26.6 eV. This narrow harmonic line still contains 1.6 mW of average power. We discuss the scaling towards higher photon flux, smaller bandwidth and potential applications

Agile spectral tuning of high order harmonics by interference of two driving pulses

In this work, the experimental realization of a tunable high photon flux extreme ultraviolet light source is presented. This is enabled by high harmonic generation of two temporally delayed driving pulses with a wavelength of 1030 nm, resulting in a tuning range of 0.8 eV at the 19th harmonic at 22.8 eV. The implemented approach allows for fast tuning of the spectrum, is highly flexible and is scalable towards full spectral coverage at higher photon energies.</jats:p

High-average-power 2 µm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate

Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed