Using the FRED Knowledge Base


Relevant knowledge base articles can be easily located using one of the following methods:

  1. Browse the Categories using the menu topics on the left of the page
  2. Enter a string in the Search box at the top left of the page

Recent Articles


Application Example: Spatial Filter

August 5th, 2016

Laser systems often use a pinhole aperture called a spatial filter. Spatial filtering is a technique used to improve laser quality by removing higher-order modes and noise in the beam. To accurately model laser propagation through a spatial filter in FRED, it is important to re-synthesize the light field just after the filter. Doing so will accurately model clipping at the aperture. In this note, a light synthesis technique called Gabor decomposition will be described.

A full description of this application example can be found here: Spatial Filter Application Example

Application Example: Polarizers

August 5th, 2016

FRED has the capability to simulate polarization of rays through an optical system. Light sources can be randomly, circularly, or linearly polarized. Optical components that filter or manipulate polarization, such as birefringent wave plates and polarizers, can be accurately modeled.

A full description of this application example can be found here: Polarizers Application Example

Application Example: Poisson’s Spot

August 5th, 2016

FRED allows for simulation of physical optics phenomena such as diffraction and interference. With this capability, components such as Gaussian laser beams and interferometers can be accurately modeled and incorporated into optical systems.

A full description of this application example can be found here: Poisson’s Spot Application Example

Application Example: Newton’s Rings

August 5th, 2016

FRED allows for simulation of physical optics phenomena such as diffraction and interference. With this capability, components such as Gaussian laser beams and interferometers can be accurately modeled and incorporated into optical systems.

A full description of this application example can be found here: Newton’s Rings Application Example

Application Example: Mobile Displays

August 5th, 2016

Mobile devices such as smartphones, e-readers, and watches are becoming ubiquitous in today’s world. Precise optical engineering is required to optimize the performance of mobile features such as the camera system, sensors, and the display. A key design objective for a mobile display is uniform illumination over its area and range of viewing angles. In addition, it should have high optical efficiency to reduce power consumption and increase battery life. Edge-lit LED screens accomplish this by using compact and efficient LED lights coupled into a transparent waveguide. Elements such as reflective back surfaces, microstructure patterns, brightness-enhancing films, and diffusers can be incorporated into the display to increase efficiency and uniformity. In this FRED model, an edge-lit LED smartphone display is virtually prototyped. Uniform illumination is achieved by incorporating a gradient diffuser along the waveguide.

A full description of this application example can be found here: Mobile Displays Application Example

Application Example: Maltese Cross Phenomenon

August 5th, 2016

FRED has the capability to simulate polarization of rays through an optical system. Light sources can be randomly, circularly, or linearly polarized. Optical components that filter or manipulate polarization, such as birefringent wave plates and polarizers, can be accurately modeled. One simple example of polarization modeling in FRED is the Maltese cross phenomenon.

A full description of this application example can be found here: Maltese Cross Phenomenon Application Example

Application Example: LED Flashlight

August 5th, 2016

Light Emitting Diodes, or LEDs, have surpassed incandescent light sources in recent years for most applications. Benefits of the LED include compact size, high power efficiency, and a long lifespan [1]. LEDs also have undesirable qualities that optical engineers must address, such as the need for color mixing and collimation. In this example we look at a simple example of a LED flashlight.

A full description of this application example can be found here: LED Flashlight Application Example

Application Example: Fizeau measurement of lens surface

August 5th, 2016

FRED allows for simulation of physical optics phenomena such as diffraction and interference. With this capability, components such as Gaussian laser beams and interferometers can be accurately modeled and incorporated into optical systems.

A full description of this application example can be found here: Fizeau measurement of lens surface Application Example

Application Example: Dichroic Cold Mirror

August 5th, 2016

The spectral distribution of a broadband light source is important to many optical systems, from white light illuminators to spectrometers. Color Image analysis in FRED produces visualization of color distribution by calculating chromaticity coordinates of each pixel and displaying the resulting RGB values over the surface. Additionally, the color chromaticity diagram is displayed, and chromaticity coordinate of each pixel is indicated when the user moves the cursor across the graph. In this application note, we look at using a dichroic “cold mirror” to split white light into two wavelength bands.

A full description of this application example can be found here: Color Image Analysis Application Example

Application Example: Color Mixing Lightpipe

August 5th, 2016

Light Emitting Diodes, or LEDs, have surpassed incandescent light sources in recent years for most applications. Benefits of the LED include compact size, high power efficiency, and a long lifespan. LEDs also have undesirable qualities that optical engineers must address, such as the need for color mixing and collimation. In this example we look at a simple example of a color-mixing lightpipe.

A full description of this application example can be found here: Color Mixing Lightpipe Application Example