Design and demonstration of fan-out elements generating an array of subdiffraction spots

Area of Science:

• Optics and Photonics
• Nanotechnology
• Computational Physics

Background:

• Diffractive optical elements (DOEs) are crucial for manipulating light.
• Generating subdiffraction features (smaller than the diffraction limit) is a key challenge in optics.
• Existing methods often struggle with precise control over spot characteristics and energy distribution.

Purpose of the Study:

• To present a novel design method for diffractive fan-out elements.
• To generate arrays of subdiffraction spots with controlled energy and phase.
• To achieve spot sizes significantly smaller than the diffraction limit.

Main Methods:

• A modified Gerchberg-Saxton algorithm incorporating a specific constraint was employed.
• The constraint controls light energy dispersion and spot phase.
• The method was demonstrated using a diffractive element for a 3x3 spot array.

Main Results:

• Simulations showed a 70% reduction in spot size compared to the diffraction limit.
• Experimental results achieved an approximately 80% reduction in spot size.
• The method demonstrated the capability to create various subdiffraction spot layouts with high signal-to-noise ratios.

Conclusions:

• The presented design method enables the creation of subdiffraction spot arrays using diffractive fan-out elements.
• The modified Gerchberg-Saxton algorithm offers precise control over light energy and phase for subwavelength features.
• This technique holds potential for advanced optical systems requiring high-resolution light manipulation.