LED flood light
  • Illumination Techniques

Design and Optimization of LED Flood Lights

LED flood lights are widely used for indoor and outdoor illumination, including billboard lighting, sports lighting, and parking lots. Compared with traditional flood lights, LED flood lights offer higher energy efficiency, longer lifetime, and better optical control.

This article demonstrates how to design and optimize an LED flood light optical system, focusing on achieving maximum flux and uniform illumination on a target area.

LED Flood Light Optical Concept

Several tools are available to model opto-mechanical designs such as LED optics. In this example:

  • A point source is used to represent the LED emitter
  • Nine reflectors shape and direct the light
  • An 80 × 80 mm square absorbing detector represents the illuminated target area
  • The detector is placed at a defined distance from the flood light
  • The flood light housing is modeled using parametric solid geometry

The objective is to maximize delivered luminous flux while ensuring good spatial uniformity across the detector.

Reference Mechanical Layout

The LED flood light designed in this article follows a mechanical concept similar to the reference drawing below, consisting of:

  • A front reflector array
  • A surrounding shell or housing
  • Grooves and mounting features

This ensures the optical design remains compatible with real-world manufacturing constraints.

https://downloads.zemax.com/zemax-portal/knowledge_articles/KA-01730/Images/01730_1_light_dimensions.png

Step 1: Create Parametric Sketches

Using the Part Designer, three sketches are created:

  • GrooveSketch – defines mechanical grooves and mounting features
  • ShellSketch – defines the outer housing geometry
  • ReflectorSketch – defines the reflective surfaces

Reflector Geometry Notes

  • The curved segment between ReflectorTop and ReflectorBottom is an arc segment
  • Arc segments are limited to half arcs
  • The radius of curvature must be larger than the distance between the arc endpoints
  • In this example, the reflector radius must be greater than 5.385 units

To allow optical optimization, the reflector radius is defined as a variable so it can be adjusted during optimization.

Step 2: Build the Optical Model

Once the sketches are completed:

  1. Return to Script Mode in the Part Designer
  2. Generate the solid geometry from the sketches
  3. Assign materials and reflective properties to the reflector surfaces
  4. Place the LED source and detector

This creates a fully parametric LED flood light optical model.

Step 3: Optimization Setup

The optimization goals are:

  • Maximize total flux reaching the detector
  • Improve uniformity across the 80 × 80 mm target

Optimization Settings

  • Detector records incident flux distribution

  • Merit Function includes:

    • Total collected power

    • Uniformity metrics (min / max / RMS variation)

  • Reflector radii and positions are included as optimization variables

Start the optimization by navigating to: Optimize → Optimize! (Local Optimization)

Optimization Results

After optimization:

  • The reflector array efficiently redirects LED light toward the target
  • Flux on the detector is maximized
  • Illumination distribution is significantly more uniform

The final optimized model represents a practical LED flood light design suitable for real applications.

Conclusion

This example demonstrates how a parametric opto-mechanical approach, combined with optical optimization, enables efficient LED flood light design. By exposing key reflector parameters and optimizing them against flux and uniformity targets, designers can rapidly converge on high-performance solutions.

The final optimized design file is provided for reference and further modification.

Reference Source

  1. https://www.zemax.com/
  2. The design file used in this article is attached as shown. How to design and optimize an LED flood light