Diffracted-ray approach to the fast evaluation of diffractive lenses

Area of Science:

• Optics and Photonics
• Computational Electromagnetics

Background:

• Diffractive lenses (DLs) are crucial optical components, but their accurate field computation in the focal region can be computationally intensive.
• Existing methods often involve complex numerical integrations, limiting analysis speed.

Purpose of the Study:

• To develop and validate a significantly faster algorithm for computing electromagnetic fields in the focal region of diffractive lenses.
• To enhance the efficiency of optical simulations involving diffractive optical elements.

Main Methods:

• Employing a combination of asymptotic methods to approximate diffractive lens behavior locally as a grating.
• Utilizing rigorous electromagnetic diffraction theory for near-field calculations.
• Deriving a simplified diffracted-ray formula for far-field focal region analysis.

Main Results:

• The new algorithm achieves a speedup factor of 3 x 10^5 compared to direct numerical integration.
• It is approximately 1000-1200 times faster than previous asymptotic methods.
• The range of validity for the derived formula was carefully investigated.

Conclusions:

• The developed asymptotic method offers a substantial computational speedup for diffractive lens field analysis.
• This advancement can significantly benefit the design and simulation of optical systems utilizing diffractive lenses.