Recursive design of a holographic focusing grating coupler

Area of Science:

• Optics
• Holography
• Waveguide technology

Background:

• Holographic optical elements (HOEs) are crucial for various optical systems.
• Waveguide focusing grating couplers (WFGCs) require precise design for efficient light manipulation.
• Aberrations in WFGCs limit performance, especially under non-ideal conditions.

Purpose of the Study:

• To present a novel method for designing and recording aberration-corrected holographic optical elements.
• To enable the creation of high-performance WFGCs suitable for diverse applications.
• To overcome limitations associated with small f/numbers and wavelength shifts in holographic couplers.

Main Methods:

• The method involves recording the holographic coupler using two predistorted wavefronts.
• These wavefronts are derived from interim holograms, allowing for different readout and recording geometries.
• This approach facilitates the correction of aberrations during the recording process.

Main Results:

• The developed holographic coupler exhibits nearly aberration-free performance.
• The method is effective even for couplers with very small f/numbers.
• Robust performance is maintained despite significant wavelength shifts between recording and readout.

Conclusions:

• The presented design and recording method significantly improves the performance of holographic optical elements.
• This technique offers a viable solution for creating advanced WFGCs with enhanced optical fidelity.
• The aberration-corrected couplers are suitable for applications demanding high precision and tolerance to varying conditions.