Bright XUV pulses with spin-orbital angular momentum control via laser-plasma mirror interaction

Area of Science:

• Laser-plasma physics
• Attosecond science
• Photonics

Background:

• Ultrafast extreme ultraviolet (XUV) sources are crucial for advanced material microstructure analysis.
• Generating bright XUV pulses with controlled spin and orbital angular momentum in compact systems is challenging.

Purpose of the Study:

• To numerically demonstrate a novel laser-plasma scheme for generating bright XUV pulses with controlled spin-orbital angular momentum.
• To achieve flexible and simultaneous control over photon angular momentum in a compact setup.

Main Methods:

• Utilizing particle-in-cell simulations to model a laser-plasma interaction.
• Employing a circularly polarized vortex laser pulse obliquely incident on a plasma mirror.
• Analyzing the topological-spectral correlation of the reflected XUV radiation.

Main Results:

• Demonstrated a linear topological-spectral relationship: the orbital angular momentum of the nth harmonic scales linearly with the driver's topological charge (m).
• Confirmed preservation of the spin state of the XUV pulses.
• Showcased the ability to construct spatiotemporal optical beams with programmable helical structures by synthesizing selected harmonic bands.

Conclusions:

• The proposed laser-plasma scheme offers a straightforward and efficient method for generating bright attosecond XUV pulses.
• This approach enables multidimensional control of photon angular momentum, advancing capabilities in ultrafast science and material exploration.
• The findings pave the way for novel applications requiring tailored XUV light properties.