Modeling Light Shaping Diffusers® in Zemax OpticStudio

Submitted on Thu, 11/10/2016 - 10:09

A unique platform developed by Luminit allows engineers and designers to accurately emulate the performance of Light Shaping Diffusers.

by Anthony Ang, Principal Optics Engineer

If you subscribe to the belief that time is our most precious resource, then you may want to explore Luminit’s new Light Shaping Diffuser scatter model for Zemax OpticStudio. We designed this proprietary optical model so customers can visualize the output distribution of a Light Shaping Diffuser and choose the right angle for their optical system, eliminating guesswork and saving hours of valuable time. The program is different from conventional optical design programs because Luminit diffusers are different from conventional diffusers.

How Luminit Light Shaping Diffusers Work

Unlike other light diffusers, Luminit Light Shaping Diffusers use holographic diffuser technology to create pseudo-random micro-lens structures. Holographic patterns are imbedded on polycarbonate or polyester sheets, and these patterns can manipulate light by changing the direction of its energy. Because it works on the principle of surface scatter instead of volume (bulk) scatter, Luminit Light Shaping Diffusers tend to have a much higher transmission efficiency and are designed to reduce the effects of diffraction, which eliminates zero order and chromatic variation (rainbow appearance).

scanning electron microscope view of light shaping diffuser

A scanning electron microscope (SEM) view of an Luminit light diffuser surface microstructure.

Scatter Model: Calculating the Result

Luminit engineers developed a proprietary optical model that accurately calculates transmission characteristics or Bidirectional Transmission Distribution Function (BTDF) of our Light Shaping Diffusers. We took this one step further and created a model that allows users to emulate the transmission distribution of Light Shaping Diffusers within the Zemax OpticStudio platform (Professional and Premium versions only). While conventional optical design programs provide bulk scatter and surface scatter models based on mathematical probabilities or algorithms that predict output distribution,  Luminit’s optical model closely emulates our characteristic Light Shaping Diffusers profiles of transmission with a large range of incident angles and wavelengths. Utilizing the Zemax  “User Defined” type of scatter model, a Luminit proprietary function defines the statistical direction of the rays which allows the shape of the diffusion to follow the Luminit Light Shaping Diffuser product.  The model is designed to scatter the light at the surface of a volume object and allows you to select the catalog angle you desire. The files take the form of a DLL (Dynamic Link Library), which is native to OpticStudio and maximizes the processing speed of the ray trace.

Examples of Measured Profiles (Left) Compared to Modeled Profiles (Right)

 

 

 

graphs showing measured profiles in zemax software

Goniometer Readings: From 1 - 30 degree, the shape of the profile is fairly Gaussian. Diffusers past 30 degrees, the shape transitions into Trapezoidal then M shaped.

 

 

Luminit Light Shaping Diffuser scatter models

 

Measures Off-Axis: Luminit’s scatter model can simulate tilted or off-axis light sources with excellent accuracy, which is particularly useful for elliptical angles. The first example is tilting a 60 degree diffuser 60 degrees. The second example is tilting a 60x1 diffuser 60 degrees.

Enhancing the Design Process

Luminit’s scatter model for Zemax OpticStudio allows engineers to make an educated choice during the design process and is just another example of how Luminit stays on the forefront of science and technology to our customers’ efforts during the design cycle. The files are available for free and can be downloaded directly from the downloads tab on this website.