On-chip switchable radially and azimuthally polarized vortex beam generation.

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Quantum Optics

Background:

• Cylindrical vector vortex (CVV) beams are complex light fields with vector polarization and quantized orbital angular momentum (OAM).
• Existing methods for generating CVV beams are often bulky and lack flexibility due to separate polarization and spatial phase manipulations.

Purpose of the Study:

• To propose and demonstrate an integrated device for generating CVV beams.
• To enable simultaneous manipulation of polarization and OAM states in a compact form factor.

Main Methods:

• Utilized a silicon nitride microring resonator with embedded top-gratings for light manipulation.
• Developed a single-step etching process for fabricating shallow-etched top-gratings.
• Experimentally demonstrated the generation of radially and azimuthally polarized CVV beams.

Main Results:

• Successfully generated CVV beams using a single integrated device.
• The device allows for the manipulation of both polarization and OAM degrees of freedom.
• Achieved generation of both radially and azimuthally polarized CVV beams.

Conclusions:

• The proposed integrated device offers a compact and highly configurable solution for CVV beam generation.
• The novel fabrication method simplifies the production of such devices, enhancing ease and flexibility.
• This work paves the way for advanced on-chip integrated photonic devices for diverse applications.