Extended-source light distribution design method based on discrete generatrix set envelope fitting and optimization

Area of Science:

• Optical Engineering
• Illumination Optics
• Applied Mathematics

Background:

• Standard optical lens design models struggle with extended light sources like LEDs, leading to uneven light distribution and blurred edges.
• Practical applications require lens designs that maintain performance with larger, non-point light sources.

Purpose of the Study:

• To develop an effective method for designing optical lenses optimized for extended light sources, specifically addressing irradiance uniformity and edge diffusion.
• To improve the performance of illumination systems using LED sources.

Main Methods:

• Discretizing an extended source into multiple point sources and using their combined envelope as an initial lens structure.
• Implementing an iterative optimization framework involving envelope fitting, ray tracing, and coefficient adjustment.
• Validating the optimized 3D lens model using ray tracing and comparing results with initial designs.

Main Results:

• Achieved a significant improvement in irradiance uniformity from 76.8% to 92.7%.
• Reduced the root-mean-square error (RMSE) of irradiance distribution from 1.625 to 0.827.
• Increased the edge irradiance gradient from 0.27 to 0.45, effectively mitigating edge diffusion.

Conclusions:

• The proposed discrete point-source generatrix set envelope fitting and optimization method successfully designs optical lenses for extended sources.
• The method demonstrates robustness and superior performance compared to initial designs and commercial software optimization.
• This technique offers a viable solution for enhancing LED illumination quality in engineering applications.