Non-iterative dartboard phase filter for achieving multifocal arrays by cylindrical vector beams

Area of Science:

• Optics and Photonics
• Nanotechnology

Background:

• Generating multifocal arrays is crucial for applications like optical data storage and parallel laser writing.
• Achieving uniform intensity distribution in multifocal arrays remains a challenge.

Purpose of the Study:

• To propose an analytically designed, non-iterative dartboard phase filter (DPF) for generating uniform multifocal arrays.
• To enhance the intensity uniformity of multifocal arrays using a novel modulation factor.

Main Methods:

• An analytically designed dartboard phase filter (DPF) was developed, divided into sectors in polar coordinates.
• A modulation factor was introduced to the DPF to improve intensity uniformity.
• Cylindrical vector beams were used to generate multifocal arrays.

Main Results:

• The proposed DPF successfully generated one-, two-, and three-dimensional multifocal arrays.
• Intensity uniformities exceeding 92.5% were achieved for the generated arrays.
• Controlled focal positions and polarization, along with subwavelength transverse spot sizes, were demonstrated.

Conclusions:

• The analytically designed DPF provides an efficient method for generating uniform multifocal arrays.
• The generated multifocal arrays offer controllable properties and subwavelength features.
• Potential applications include polarization-multiplexed data storage, nanophotonic devices, and laser writing.