FRED Knowledge Base

CIE 1931 Color Matching Functions

The attached FRED file contains three sampled spectra, one each for the x, y and z color matching functions.  All three spectra can be selected on the tree simultaneously and the Plot option can be selected from the right mouse click context menu so that...

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Scripting Subroutines and Functions

Scripting in FRED is a very powerful capability for automating custom calculations or performing iterative tasks that would be difficult to do through the GUI.  When creating scripts, users should think in advance about whether certain portions of the script are likely to be performed...

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Composite Ray Buffer – Scanner Example

This knowledge base article demonstrates how to use auxiliary ray buffers for the purpose of temporarily storing rays of interest in a system.  In this particular example, a ray bundle is scanned over a target using a rotating pentagonal reflector.  The goal of the simulation...

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Hemisphere Volume Emitter

This knowledge base example demonstrates how to create a hemisphere volume emitter.  Detailed source models allow for volume emitters in the shape of spheres, cylinders and boxes but no default functionality for hemispheres.  The approach for creating a hemisphere volume emitter is a hybrid of...

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Optimizing Lens Modules

The Lens Module family of surfaces (Infinite conjugate, finite conjugate, afocal and spherical) provide a convenient mechanism for quickly defining an ideal lens element.  If the circumstance arises where a lens module surface is desired to be included in an optimization, the user will find...

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Scripted Encircled Energy for ARNs

This knowledge base article demonstrates how to calculate the encircled energy in an ARN by scripting.  The FRD file contains a simple gaussian source and analysis surface as well as an embedded script.  The embedded script will calculate the irradiance on the analysis surface and...

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Batch Processing Raytraces Using COM

“Batch-Processing.frs” demonstrates how to run a sequence of raytraces using FRED’s COM capability. The script is kept generic by retrieving and executing the code in the Embedded Script of each FRED Document that is opened. The additional FRED Document “run1.frd” provides a simple demonstration of...

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Laser Diode to Fiber Coupling Analysis

This knowledge base article discusses how to use FRED to accurately model the coupling from a ball-lens capped semiconductor laser diode to a single mode fiber – an optical system common in optical fiber communication applications. This model demonstrates FRED’s capability to propagate coherent fields,...

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Telescope Model Using OAPs

This knowledge base article demonstrates modeling of a three mirror 5x afocal telescope system as prescribed in “Modern Lens Design: A Resource Manual” by Warren Smith (McGraw Hill).  This article discusses how to construct the off-axis parabolas (OAPs) in FRED using the surface apertures to...

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