Martin Luttmann

• PhD
• Scientist at Swiss Federal Institute of Technology in Lausanne

The laser excitation of magnetization dynamics without applying external fields is a topic of high interest for its potential applications (e.g., magnetic memories, oscillators, and THz emitters). We explore the use of an ultrashort infrared laser pulse for triggering transient changes in a magnetic vortex, probing the induced dynamics by time-reso...

The notched stick, also known as the Gee-Haw-Whammy-Diddle, is a wooden toy able to convert linear vibration into rotational motion, whose behavior has been intriguing both children and physicists for decades. The oldest scientific article one can find on this subject was published 87 years ago in the present journal. Here, we derive an analytical...

The notched stick, also known as the Gee-Haw-Whammy-Diddle, is a wooden toy able to convert linear vibration into rotational motion, whose behavior has been intriguing both children and physicists for decades. Here we derive an analytical model of the system, supported by experimental results. We predict the direction of rotation, and explain why t...

The rotational symmetries of a light beam are linked with angular momenta. Thus, the spin and orbital angular momentum are respectively related to the rotational invariance of the polarization vector and of the spatial distribution of the light field. They may take values which are integer multiple of ℏ. In some cases, a generalized angular momentu...

We report on the generation of optical vortices with few-cycle pulse durations, 500μJ per pulse, at a repetition rate of 1 kHz. To do so, a 25 fs laser beam at 800 nm is shaped with a helical phase and coupled into a hollow-core fiber filled with argon gas, in which it undergoes self-phase modulation. Then, 5.5 fs long pulses are measured at the ou...

This paper is a joint publication with the paper by Vimal et al. [Phys. Rev. Lett. 131, 203402 (2023)]. High-order harmonic generation (HHG) is an extreme nonlinear optical phenomenon at the heart of modern ultrafast physics. When HHG is driven by two noncollinear beams, one being significantly weaker than the other, the yields of the harmonic emis...

High harmonic generation (HHG) has become a core pillar of attosecond science. Traditionally described with field-based models, HHG can also be viewed in a parametric picture, which predicts all properties of the emitted photons, but not the nonperturbative efficiency of the process. Driving HHG with two noncollinear beams and deriving analytically...

Exotic light fields combining non-trivial spin and angular momentum may not be eigenstates of either the spin or orbital angular momenta operators. For these fields, it is relevant to define a Generalized Angular Momentum operator of which they are eigenvectors. Their associated eigenvalues can take, depending on the case, non-integer values. We re...

Symmetries and conservation laws of energy, linear momentum, and angular momentum play a central role in nonlinear optics. Recently, paraxial light fields with nontrivial topology have been attracting a keen interest. Despite not being eigenstates of the orbital and spin angular momenta (OAM and SAM), they are eigenstates of the generalized angular...

We present the commissioning of the FAB10 beamline (Femtosecond to Attosecond Beamline at 10 kHz repetition rate) that has been developped and operated in the last few years at the ATTOLab facility of Paris-Saclay University. Based on the high harmonic generation process, the beamline is dedicated to investigations of ultrafast dynamics in a broad...

Circularly polarized light is a fundamental tool in magnetic studies, notably for magnetization dynamics. It is less common in magneto-optics to exploit the orbital angular momentum (OAM) of value ℓ carried by light beams possessing a helical wavefront. After finding many applications in the visible range, recently OAM pulses with ultra-short durat...

Symmetries and conservation laws of energy, linear momentum and angular momentum play a central role in physics, in particular in nonlinear optics. Recently, light fields with non trivial topology, such as polarization Möbius strips or torus-knot beams, have been unveiled. They cannot be associated to well-defined values of orbital and spin angular...

We report on the experimental evidence of magnetic helicoidal dichroism, observed in the interaction of an extreme ultraviolet vortex beam carrying orbital angular momentum with a magnetic vortex. Numerical simulations based on classical electromagnetic theory show that this dichroism is based on the interference of light modes with different orbit...

We report magnetic helicoidal dichroism (MHD) in the interaction between XUV beams carrying orbital angular momentum and magnetic vortices. The results match theoretical predictions and confirm the potential of MHD for studying laser-triggered ultrafast dynamics in complex magnetic materials.

We report on the experimental evidence of magnetic helicoidal dichroism, observed in the interaction of an extreme ultraviolet vortex beam carrying orbital angular momentum with a magnetic vortex. Numerical simulations based on classical electromagnetic theory show that this dichroism is based on the interference of light modes with different orbit...

The flourishing of attosecond science (1 as = 10−18 s) has created a need to control exquisitely the delay between two ultrashort light pulses, where one of them is intense and in the visible spectral range, while the other is weak and in the extreme-ultraviolet spectral range. Here we introduce a robust technique, named LIZARD (Laser-dressed IoniZ...

We present the classical electromagnetic theory framework of reflection of a light beam carrying orbital angular momentum (OAM) by a magnetic structure with generic symmetry. Depending on the magnetization symmetry, we find a change in the OAM content of the reflected beam due to magneto-optic interaction and an asymmetric far-field intensity profi...

In a recent work [1], we demonstrated how laser-dressed ionization can be harnessed to control with attosecond accuracy the time delay between an extreme-ultraviolet (XUV) attosecond pulse train and an infrared (IR) femtosecond pulse. In this case, the comb-like photoelectron spectrum obtained by ionizing a gas target with the two superimposed beam...

The blooming of attosecond science (1 as = $10^{-18}$ s) has raised the need to exquisitely control the delay between two ultrashort light pulses, one of them being intense and in the visible spectral range, while the second is weak and in the Extreme Ultra-Violet spectral range. Here we introduce a robust technique, named LIZARD (Laser-dressed Ion...

In the joint publication XX XXX XXXXXX we report the prediction of a Magnetic Helicoidal Dichroism (MHD) in reflection of a light beam carrying Orbital Angular Momentum (OAM) by a magnetic vortex. It is due to a change of the OAM content of the outgoing beam, which depends on the curling sense of the magnetization and of sign of the OAM. In this pa...