Programmable generation of counterrotating bicircular light pulses in the multi-terahertz frequency range

Area of Science:

• Ultrafast photonics
• Solid-state physics
• Nonlinear optics

Background:

• Intense infrared and terahertz light fields are crucial for manipulating solid states.
• Counterrotating bicircular light offers unexplored potential beyond conventional circular polarization.
• Experimental generation of these fields in the mid-infrared/multi-terahertz range faces challenges in phase stability and polarization elements.

Purpose of the Study:

• To overcome experimental challenges and generate phase-stable counterrotating bicircular light pulses.
• To enable programmable control over bicircular light field properties.
• To advance the understanding and application of tailored light fields in solid-state materials.

Main Methods:

• Spectral broadening of near-infrared pulses.
• Polarization pulse shaping using a spatial light modulator (SLM).
• Intra-pulse difference frequency generation in a nonlinear crystal, utilizing angular-momentum selection rules.

Main Results:

• Successful generation of phase-stable counterrotating bicircular light pulses in the 14-39 THz range.
• Direct conversion from near-infrared to designed multi-terahertz bicircular pulses.
• Programmable control over the shape, orientation, symmetry, and helicity of the light field trajectory via SLM.

Conclusions:

• This work presents a novel method for generating tailored counterrotating bicircular light fields.
• The developed technique circumvents previous experimental limitations in phase stability and polarization control.
• This advancement opens new avenues for light-matter interaction studies, particularly for topological semimetals.