Tailoring freeform illumination optics in a double-pole coordinate system

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Designing freeform illumination optics presents challenges in achieving high accuracy and uniformity.
• Existing coordinate systems can lead to significant surface errors and uneven light distribution.

Purpose of the Study:

• To introduce and validate a new double-pole coordinate system for designing freeform illumination optics.
• To demonstrate the method's capability in reducing residual surface error and enhancing illumination uniformity.

Main Methods:

• Development of a double-pole coordinate system by repositioning the poles of a spherical coordinate system.
• Application of the new coordinate system to ray mapping in freeform optical design.
• Comparison of residual surface error (RSE) with conventional (θ,φ) and (u,v) coordinate systems.

Main Results:

• The double-pole coordinate system establishes a more accurate ray mapping.
• Significant reduction in surface error and substantial improvement in illumination uniformity were achieved.
• The RSE of lenses designed with the double-pole system was one order of magnitude smaller than with the (θ,φ) system and 1/3 of that with the (u,v) system.

Conclusions:

• The double-pole coordinate system offers a superior approach for freeform illumination optics design.
• This method effectively minimizes optical surface errors and enhances light distribution quality.
• The findings suggest a significant advancement in the precision and efficiency of freeform optical element fabrication.