Chiro-optical fields with asymmetric orbital angular momentum and polarization.

Area of Science:

• Optics and Photonics
• Quantum Optics

Background:

• Conventional chiro-optical fields typically exhibit rotational symmetry.
• Existing methods often rely on superposition of symmetric vortex beams, limiting control over local properties.

Purpose of the Study:

• To propose a novel method for generating asymmetric chiro-optical fields.
• To achieve local control over orbital angular momentum (OAM) and polarization states within chiro-optical fields.

Main Methods:

• Utilized a helix phase plate (HPP) based on coordinate transformation of perfect vortex beams for OAM controllability.
• Employed the transformation matrix method to stitch discrete chiro-optical fields into multi-lobed structures.
• Designed HPPs for spatial light modulators to independently control polarization in each side-lobe.

Main Results:

• Demonstrated the generation of asymmetric chiro-optical fields with locally controllable OAM.
• Successfully created multi-lobed fields with asymmetric OAM distribution across side-lobes.
• Achieved independent modulation of polarization states for each side-lobe.

Conclusions:

• The proposed method breaks the uniform OAM and polarization distribution of conventional fields.
• Asymmetric chiro-optical fields offer potential applications in optical tweezers, communications, and enantiomer-selective sensing.