Circular grating coupler for creating focused azimuthally and radially polarized beams

Area of Science:

• Photonics and Optical Engineering
• Nanotechnology
• Materials Science

Background:

• Generating focused, polarized light beams is crucial for advanced optical applications.
• Existing methods often require bulky external components for beam manipulation and focusing.
• Integrated photonic solutions offer miniaturization and enhanced functionality.

Purpose of the Study:

• To design and demonstrate a compact planar optical circuit for generating focused, azimuthally or radially polarized beams.
• To achieve subwavelength focal spot sizes using an integrated silicon-on-insulator (SOI) platform.
• To explore the potential applications of such a device in various fields.

Main Methods:

• Design of a planar optical circuit utilizing silicon-on-insulator (SOI) waveguides.
• Simulation and analysis of light propagation and focusing within the designed circuit.
• Characterization of the generated polarized beam and its focal spot properties.

Main Results:

• Demonstration of a planar optical circuit capable of producing focused azimuthally or radially polarized beams.
• Achieved subwavelength focal spot sizes without external focusing elements.
• Successful implementation in SOI waveguides, highlighting material compatibility.

Conclusions:

• The proposed planar optical circuit offers a novel and integrated approach for generating focused polarized light.
• The subwavelength focusing capability opens new avenues for high-resolution optical applications.
• This SOI-based design provides a scalable and efficient solution for advanced photonic devices.