FRED Test Flight

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FRED

Test Flight Copyright 2005 Photon Engineering, LLC All Rights Reserved - Page 1

Display Systems

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FRED - Test Flight

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FRED


Photon Engineering LLC440 S. Williams Blvd, Suite #106Tucson, AZ 85711

520-733-9557520-733-9609support@photonengr.comwww.photonengr.comRevised: December 19, 2005
http://www.photonengr.com/http://www.photonengr.com/http://www.photonengr.com/


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Table of Contents

Installation, Basics and Mechanics of FRED

Table of Contents ..............................................................................................3Welcome to FRED!............................................................................................4Installation ......................................................................................................5FREDUpdates .................................................................................................5Copy Protection ................................................................................................5FREDsDocument View Architecture......................................................................6Defining Objects................................................................................................8The Commands: the Menus, the Toolbars, and the System Tree view .............................. 13

The Output Window and the Command Line.......................................................... 14Copy-and-Paste ............................................................................................ 15Drag-and-Drop ............................................................................................. 16Visualization................................................................................................ 16Multiple Document Support.............................................................................. 19

Tutorials

Tutorial Introduction ........................................................................................ 19The Simple Lens Tutorial.................................................................................... 19The Elliptical Reflector Tutorial ........................................................................... 29

What Are Coatings?........................................................................................ 32What are RayTrace Controls? ............................................................................ 33Default Coating Definitions .............................................................................. 33

More Sample Systems........................................................................................ 45More Online Tutorials........................................................................................ 46Search Utility ................................................................................................. 47Getting Started on Your Own............................................................................... 47

Sample FREDApplications and Outputs ................................................................. 48

FREDis a proprietary product of Photon Engineering, LLC, Tucson, Arizona.Other trademarks or marks are the property of their respective companies.

FRED



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Welcome to FRED!

FRED

Welcome to the growing ranks of FRED users! FRED is a unique program for opticalanalysis. It is extremely powerful, yet has been developed for maximum ease of use. It isreadily learned by those who have never used optical software before, and yet is also easy tolearn for those who have experience with the user interfaces of other optical software

products. FRED sintuitive tree-like data structure allows easy management of all of the data

required to describe a complex optical system. Despite all the power and flexibility in FRED ,

you will find that FRED has a much faster learning curve than almost any other softwareproduct you have used. In almost no time at all, you will be building complex optical systemsand performing precise, detailed analyses. The WYSIWYG (what you see is what you get)user interface gives confidence that your model is correct, and is what you intended. You can

use FRED with confidence that your answers are accurate. FRED has been thoroughlytested to be sure your model's results will agree with the as-built system.

An optical system in FRED is referred to as a documentrather than as a lens file. That'sbecause the total system data will contain more than just the lens data; it includes data on themechanical structures, sources, coatings, surface properties, etc. The data required to define

the entire optical system in FREDis kept in a tree-like data structure similar to that used by

Windows Explorer; if you can use Explorer, you can manipulate FRED sdata structure. It

allows drag-and-drop and cut-and-paste within a given FRED document and even between

multiple FRED documents! This gives you maximum flexibility, for example, to build andanalyze subsystems of your overall optical system, and then put them together for a completeend-to-end analysis.

To assist in building your overall optical system, FRED can read in lens files fromCODE V, Zemax, OSLO, and ASAP, as well as import CAD structures defined in IGES orSTEP file formats. It also has an up-to-date database of commercially available lenses and

prisms from many major US suppliers; all can be easily imported into any FRED document.

It is beyond the scope of this Test Flightto give examples, but FRED can also interface

with other programs such as Excel, MathCad, Matlab, etc.FRED

can call other programs orbe called by them. FRED has a built-in compiler for Visual Basic, making it easy to generatescripts to build complex custom elements or perform complex analyses (or loops of analyses).

FRED has been made easy to use, yet very powerful, because like you, we use it ourselvesto perform optical analyses for our engineering consulting customers and we want ouranswers to be as complete and accurate as possible just as you do!

This Test Flight is written to help you get started. There are additional tutorials and

examples on many different optical topics on-line in FRED . Simply go to HelpTutorials .And if you have any additional questions, simply contact us by phone or e-mail. We want you

to be successful with FRED !

We firmly believe that the more you use FRED , the more amazed you will be with it!



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Installation

Installation is quick and straightforward. Place the FRED CD in your computers CDROM drive. After a few seconds the installation procedure should automatically begin. If itdoes not, then run the autorun.exe or setup.exe file located on the CD.

If your system does not have the latest Microsoft installer, it will be automatically installed

on your PC prior to the installation of FRED itself. You will be required to reboot yourcomputer to continue the installation. This step is skipped if you already have the latestinstaller.

FREDUpdates

If you have purchased a copy of FRED you are entitled to download all updates of FRED that become available during the time your support period is valid. These updates are madeavailable on our internet download site on an approximately monthly basis and occur in twoforms: release updatesand intermediate updates. Release updates occur approximately twice

per year. Intermediate updates occur approximately every other month. We also make thelatest release notes available for separate download to help you decide if the latest update isappropriate for you. Contact Photon Engineering, LLC sales or support for the download link.

The intermediate updates are labeled as such and contain the latest new features andfixes. We do notmake buggy versions available for download just for the sake of meeting amonthly deadline, but the new features may not have the depth of testing that is desirable foran official release. Many users have already taken advantage of this great opportunity and ithas been a great success.

Before you download you should make sure that your software support status authorizes

you to run the version of FRED you wish to download. Check by starting your current version

of FRED and then selecting the License Authorization menu item in the Help main

menu.

Copy Protection

FRED


Hardware key. The release version of FRED is copy protected using a hardware key

that you plug into your computers parallel port (or optionally, the USB port). FRED will not

run unless the key is plugged in. You may install FRED on more than one computer, but only

one copy of FRED may run at any one time. For example, it is permissible to install FRED at work and at home. Under this scenario you can simply remove the key from your PC at workand take it home with you at the end of the day, and vice-versa. The demo version of FRED isnot hardware key protected and so the above explanation does not apply in that case.

Defective, Lost, or Stolen Hardware Keys. In the unlikely event that a hardware keybecomes defective, we will exchange the defective key with a replacement key. As for lost orstolen keys, it is your responsibility to protect your hardware key as you would protect anyasset of comparable value. Photon Engineering is NOT responsible for replacing lost or stolenkeys.


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Why is FREDDifferent?

FRED is an Optical engineering software that picks up where other lens design

software leaves off. With the FRED optical engineering software, the analyst merges the

optical elements with the mechanical components to build a complete, integrated overallsystem model. Frequently this is the first time in the product development process where theoptical and mechanical parts are together in the same model, and so any mismatchedelements, incorrect separations and/or locations, inconsistent dimensions, the same lens hasto be in two places at once, etc., are readily identified.

This integrated model serves as a basis for performing real world analyses of the

performance of the complete opto-mechanical system. For example, FRED is routinely usedto analyze and quantify all types of systems, lens designs, illumination systems, and stray lightproblems in optical systems.

FREDsDocument View Architecture

The FRED graphical user interface (GUI) is very similar to most Windows programs, but

it has been tailored to the needs of optical design and analysis. A FRED document can beconsidered as a stand-alone optical system consisting of at least one or more of the followingseven major object types:

Optical sources Objects that describe the wavelengths, positions, angles,wavelength apodization (weighting), position apodization, angle apodization,coherence, and flux of rays to be created. Note that sources are NOT rays, theyare only the definitions of the ray starting points and directions.

Geometry Objects that describe elements that are made of surfaces andcurves. This includes optical as well as mechanical geometry.

Analysis surfaces Objects that allow the analysis of ray positions, directions,irradiance, and intensity. These can be placed on any surface in the opticalsystem.

Materials Objects that are assigned to surfaces to describe the complexrefractive index (n-ik) properties of the surfaces using the geometry and coatings.

Coatings Objects that are assigned to surfaces to describe the reflection,transmission, and absorption characteristics of the surfaces. These can be

entered as coefficients or as thin film coating layers. The coatings allow FRED

to maintain correct radiometry through a raytrace.

Scatterers Objects that are assigned to surfaces to describe the scatterproperties of a surface.

Raytrace Properties Objects that are assigned to surfaces to describewhether reflected and/or transmitted rays are traced from the surface. Theseobjects also control how many ray splits are allowed (children) for a given parentray.

FRED



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The FRED user interface comes complete with menus, toolbars, system tree,visualization view, text output window, status line, and command line. The user interface

has standard Windows Menu items at the top of the FRED document interface that

features drop down lists when selected. This Menu list includes all of FRED sfunctionality with the Tools, Raytrace, 3D View, Create, and Analyses menus.

The Toolbar features many standard Windows icon buttons to open documents, cut-and-paste folder operations, undo/redo functions, and more. The toolbar is customizable and,

besides including many standardFREDfunctions for raytrace, analyses and viewing, can becustomized to add or delete icons for almost everyFRED menu item.

The visualization area is the main viewing area to verify geometry generation. This areacan be set to view two-axis profiles, X-Y, X-Z, Y-Z or any combination of these two axes, orarbitrary views from any 3D direction. It is also possible to use the trackball to manipulate anyview or directly input viewing coordinates into the Tools Preference Visualization menudialog.

The text output area can be selected to be either spreadsheet-like with cells containingoutput information, or similar in functionality to a notepad where output results are simplyshown in text format. The preference for spreadsheet or notepad-like is set in the View Output WindowCells menu.

The status window is menu-specific and can show everything from cursor coordinatesdetailing where the cursor is on the visualization window when active to showing the functionselected when using menu or tool bar items. The status window also shows the system and

FRED



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wavelength units in the bottom right hand corner. Finally the command line can be used to

directly enter enhancedFREDbasic script commands.

EachFREDdocument has a system tree which provides a hierarchal organization of the

FRED document and contains the 7 folders of information specific to each document:Geometry, Analysis surfaces, Materials, Coatings, Scatterers, and Raytrace Properties. A

node in the system tree view refers to one of these folders and consists of an icon, title, and adescription as shown below.

Defining Objects

To define or enter objects, such as a lens or mirror, in FRED , you right click on theappropriate node in the system tree. This will bring up a menu of actions; choosing to enter anew object will then bring up a dialog box in which you enter the parameters for the object tobe entered. As you enter the parameters, you can click Apply to see how the object is beingcreated before you enter other parameters. You click on OK to finalize the entering of theobject.

When an object is entered into a FRED document, it is listed under the appropriate node.A node with objects can be expanded to show the objects or collapsed to hide the objects,similar to the Windows Explorer. A collapsed node has a symbol in front of the node andan expanded node has a symbol in front of the node. To expand or collapse a node, leftmouse click on the or symbols respectively. For example, expanding the Materials nodewill show all the materials currently in the document. The materials shown below are in all

FRED documents by default.

FRED



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To create a lens element is a simple process. First, right mouse click on the GeometryFolder in the system tree to have the geometry creation menu appear. Then select the CreateNews Lens menu option to have the Create a New Lens Dialogue appear. Accept thedefault lens information by Left mouse clicking on the OK button to create the lens as shown inY-Z profile below. Notice that if you click on the + sign in front of the lens node, the systemshows that the lens is comprised of three surfaces, the front, back and edge of the lens. So alens primitive in FRED creates a solid with all three surfaces automatically created to define acomplete solid bounded object.

FRED



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Objects (curves, surfaces, lens, prisms, mirrors, custom elements, and subassemblies) in

FRED are located by default at the global origin in the Y-Z plane. After making a surface,custom element, lens, mirror, prism or subassembly you can move this object by right mouseclicking on the object in the geometry folder, and then selecting the option to position theobject. Objects can be positioned in global space, or in reference to any other positionedobject. This is particularly useful if you only know the distance of this object in reference to

another object which is often the case in optical designs. Most objects often have a specifictab on the Edit dialogue which allows them to be defined directly or can be modified directly intheir creation dialogue. Please note that it is best to group curves and surfaces together intocustom elements and subassemblies and position all of these objects at one time by definingthe correct position on the custom element or subassembly. Shown below is the lens creationdialogue showing the many reference coordinates available to position a lens.

After selecting the reference coordinate system you can then right mouse click on the 0reference coordinate and append a change to the position by selecting the appendmodification, selecting the reference coordinated action and the shift, rotation or change to theposition of the object as shown below.

FRED



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The hierarchy of the geometry building in FRED works as follows:

The Geometry Folder can contain:

Subassemblies

Elements

Lens Dynamic, know how to create and maintain themselves

Mirror Dynamic, know how to create and maintain themselves

Prism Dynamic, know how to create and maintain themselves

Custom Element static they defined by the user, contain user defined surfaces

and curves

A Subassembly can also contain:

Other Subassemblies

Elements (Mirrors, Lenses, Prisms or Custom types)

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An Element can contain:

Surfaces created directly or used as trimming surfaces (implicit surfaces)

Curves used to create explicit surfaces by extrusion, revolution or ruling, or to beused as a trimming curve

A Surface can contain:

Curves used to create explicit surfaces by extrusion, revolution or ruling, or to beused as a trimming curve

The figure below is an excellent example of the geometry hierarchy with subassemblies,elements, surfaces and curves called out under the geometry folder.

FRED



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The Commands: the Menus, the Toolbars, and the System Tree view

All of the commands in FRED are available through a left mouse button click on theappropriate menu item,

a leftmouse click on the appropriate toolbar item,

or a right mouse click on the appropriate node in the system tree view.

Generally, if you want to perform an action with the information in a FRED document,you do so with either a menu item or toolbar item. If you want to add or change an object in

the FRED document, then rightclick on the appropriate node of the system tree and make aselection in the pop-up menu.

FRED



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The Output Window and the Command Line

The results of actions taken with the information in a FRED document are listed in theoutput window. For example, if a raytrace is performed then the results of the raytrace arelisted in the output window (as shown below). In addition, the coordinates of the cursor in the

visualization window are shown below the output window and command line.

The output window is actually a spreadsheet. The view of the output window can betoggled between a plain text format (Notepad-like) or a spreadsheet format with cells similar toExcel in the View menu (ViewOutput WindowCells).

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Commands can be typed in manually on the command line. Presently, any of theenhanced BASIC scripting commands can be entered into the command line; multiplecommands on the same line are separated by colons.

You can change the color of text, numbers, and formulae in the output window in theformat page of the preferences dialog (Tools Preferences Format). This format page

handles both the output window and the script editor so you need to select the output windowas the category before you can change the output window colors.

Copy-and-Paste

Most objects in FRED including geometry objects, materials, coatings, and optical

sources can be copied and pasted using the copy command, , (Ctrl+C) and paste

command, , (Ctrl+V). The exception to this is the output window, which is actually aspreadsheet. For operations inside the output window, use the output window commands,

which are print, cut (Shift+Ctrl+X), copy (Shift+Ctrl+C), and paste(Shift+Ctrl+V) respectively. If you want to copy a raytrace result from the output window into a

dialog box text window, then you use , (Shift+Ctrl+C), to copy out of the output window

spreadsheet and , (Ctrl+V), to paste into the dialog box text window.

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Drag-and-Drop

A quicker alternative to copy-and-paste is drag-and-drop. All FRED geometry objects,materials, coatings, and sources can be dragged and dropped to make copies. To makecopies with drag-and-drop, simply left mouse click on the object to be copied and while

pressing the Ctrl key and holding the left mouse button down, drag the object to another nodein the same section of the system tree and release the mouse key and then the Ctrl key.When you press the Ctrl key, you will get a + next to the cursor, indicating a copy is beingmade.

To move an object with drag-and-drop, leftmouse click on the object to be moved anddrag the object to another location in the same section of the system tree.

In the case of materials and coatings, they can be dragged and dropped onto geometryobjects to apply them to geometry objects. You do not need to hold down keys to apply amaterial or coating using the drag-and-drop method.

Visualization

The visualization window can be zoomed, translated, rotated, etc., using the visualizationwindow toolbar controls.

FRED



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The trackball option, , allows the user to spin the objects about a fixed point. Thedefault fixed point is the global origin. The fixed point can be changed to any surface in the

FRED document by placing the cursor over the object, pressing the Ctrl key, and left mouseclicking on the object. You may have to turn off other objects to get a clear view of the objectyou wish to make the center of the rotation.

If you want something to be visible in the visualization window (and raytraced), then theobject must have the Traceable toggle switch turned on. This option is available in the rightmouse click pop-up menu. When entering a new item in the geometry, the default is to betraceable.

When you left mouse click on a geometry or source object in the FRED tree view, then abounding box around that object is traced out in REDin the visualization view. This helps youverify the proper item is selected.

The color, transparency, and surface drawing mode of an individual surface can bechanged in the visualization page of the surface edit dialog. To display this dialog page, rightmouse click on the surface you would like to edit, and choose "Edit/View Surface...".

From there, click on the Visualization tab, shown on the next page.

FRED



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There are times when the rendering of an object is poor or non-existent because theobject is fairly small compared to the Outer Trimming Volume. If an object is not renderingproperly in the visualization window (and it is set as Traceable) then reducing the tessellationin the visualization page of the surface edit dialog will likely fix the problem (see the right handside of the Visualization page).

The color, transparency, and surface drawing mode can be changed for all the objectshighlighted in the tree with the Color Attributes dialog available in the pop-up menu from arightmouse click on any geometry node. When selecting a color for an object, be sure to clickthe Assign box before clicking OK.

FRED



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Multiple Document Support

FRED will allow multiple independent documents to be open at the same time. Thismakes it easy to compare and contrast systems and to copy-and-paste from one document toanother. It should be noted that the objects and system raytrace information in any given open

FRED

document is independent of any other openFRED

documents.

Both the drag-and-drop option and the copy-and-paste option can be done inside of onedocument or between multiple documents. If you apply a material or coating from onedocument to another document via a drag-and-drop, the material or coating is automaticallyadded to the materials or coating node respectively and will be available inside the destinationdocument for future use.

The GUI interface is discussed in more detail in the user interface section of the help files.

Tutorial Introduction

This tutorial provides an introduction to the basic principles of using the FRED OpticalEngineering Software.

First, we will launch the FRED software, get a brief summary of its major user interface

components, and create a default FRED document. Then we will create a lens, an opticalsource, and a detector plane in the document. Finally, we will trace the rays from the source tothe detector and generate a spot diagram.

As we work through the tutorial you will probably find it very helpful to run FRED at thesame time. You may also find it convenient to position the tutorial window on one side of your

computer screen andFRED on the other.

The Simple Lens Tutorial

You can start FRED by going to the desktop and double-clicking on the FRED icon, or

from the Start Menu select Programs Photon Engineering FRED Optical Engineering

Software. The FRED windows initial appearance is as shown below and does not contain a

FRED document yet.

FRED



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From the main menu select FileNewFRED Type (or press CTRL+N). This creates

a newFRED

document, but does not close any already openFRED

documents.

FRED

http://c/Eudora/Eudora/attach/Menu-File-Commands.htmhttp://c/Eudora/Eudora/attach/Menu-File-New.htmhttp://c/Eudora/Eudora/attach/Menu-File-New.htmhttp://c/Eudora/Eudora/attach/Menu-File-Commands.htm


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The FRED document window has two major areas: the system tree view on the left andthe 3D visualization view on the right. The system tree view shows all of the items that are

defined in the FRED model such as elements, surfaces, optical sources, coatings, etc. The3D visualization view shows the physical appearance of the model geometry. Currently thiswindow just shows the Z coordinate axis in blue pointing to the right and the Y coordinate axisin green pointing upward. The X coordinate axis (in red) is pointing into the paper. This initial

orientation of the coordinate axes can be set under the Visualization tab of Tools

Preferences.

The black background as shown above can be changed to any user-defined color usingthe Tools Preferences Visualization menu by changing the Screen Backgroundselection. For all further screen captures in this Test Flight, the screen background has beenchanged to white for easier visibility of the details.

Now that we have a FRED document, we are ready to create our optical system. For

many of its features,FRED uses pop-up menus accessed via a rightclick. In fact, this is

how we tell FRED that we want to create a new lens. Rightclick on the Geometry folder inthe Tree View and select Create New Lens . Alternately, we could simply choose the NewLens menu item under the Create main menu.

FRED



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The Create a New Lens dialog will appear (shown on the next page). This dialog iswhere you specify all the properties of the lens. Note that the choice of whether to enter radiusor curvatures can be set under Tools Preferences Miscellaneous; similarly, the systemdimensions (e.g., inch or millimeter) can be set under Tools Preferences Units ofMeasurement.

We will create a lens with a focal length of 10 and accept the default values for the otherparameters. Under Basic Parameters, select Focal Len/Bend for the Parameter Type. Inthe Focal Length box, enter 10. Then click the OK button to create the lens. The "FocalLen/Bend" option will automatically set the lens radii according to the bending parameter toachieve the desired focal length. If we had chosen to enter radii, the dialog box entries wouldchange to let us enter the front and back radii.

We will choose to use the default Standard Glass, which is similar to Schott BK7. If wewanted to specify a particular glass, we would click on the Glass button, which allows us toselect a glass catalog and glass type. All the major glass manufacturers' catalogs are included

in FRED .

FRED



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Now that you have created the lens, go to the tree view and click the + sign next to theGeometry folder to see the icon for the lens you just created. You will also see thevisualization of the lens in the 3D view. If you click on + sign next to the icon that looks like alens under the Geometry folder you will see the surfaces and edge that comprise the completelens object as shown.

To get a better view of the lens, click in the 3D view, then on the main menu select 3D

View Trackball Mode (or click on the Trackball icon ). Click anywhere in the 3D viewand drag the mouse around while holding down the left mouse button. While you drag themouse around, the visualization view rotates the image of the lens.

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Now we'll create the source for the rays. Rightclick on the Optical Sources folder in theTree View and select Create New Simplified Optical Source. This will allow us to define asimple collimated source. The default is monochromatic at 0.5875618 microns (sodium d line).

A Create a New Source dialog box will appear. We will keep the choice of "Collimatedsource (plane wave)." In the parameters box below Type:, enter 0.4 for the X semi and Ysemi. Enter 5 for X num and Y num. Under Location/Orientation, rightclick and selectAppend in the pop-up menu. For the Z parameter of the Shift action, enter 10. Change theray color to red in the Wavelength List section by clicking on the down arrow under the RayColor selection and selecting red from the palette. Click the OK button in the upper right

portion of the menu dialog to accept all the changes you have made to this dialog and to enterthe source.

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After adding the source we will want to expand the 3D view so that we can see both thesource and the lens. Go to the main menu and select 3D View View All to rescale the 3D

view so that all of the geometry is visible. Or you can use the View All icon or press theF10 key. Note that if your mouse has a wheel, rolling the wheel will change the scale of the 3DView.

Go to the main menu and select Ray Trace Trace and Render (or you can use the

Trace and Render icon ). The rays will start from the source and propagate through thelens, changing from solid lines to dashed lines after they leave the lens. The dashed linesmeans that the rays do not intersect anything after leaving the lens.

Now we'll create the image plane. Unlike creating a lens, creating a plane requires twosteps. First we create a custom element, and then we create a single plane surface on theelement.

In the system tree view, right click on the Geometry folder and select Create NewCustom Element. The Create a Custom Element dialog will pop up. We will move thecustom element to the Z=10 position. In the Position/Orientation box right click and selectAppend. This allows you to append an operation, such as a shift or rotation, to position the

object exactly where you want it. In some cases, multiple append operations may be neededto position an object exactly where you want it and in the correct orientation. In this case, we

just want a simple shift in Z. In the Z column of the Shift Action, enter 10. Click the OK buttonon the dialog to create the custom element. Note that the element doesn't appear yet in the3D View, because there are no surfaces yet as part of this element, and thus there's nothingto see.

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We can now create a surface for the custom element. In the tree view, expand theGeometry node if needed (click on the "+" sign next to Geometry) and rightclick on Elem 1and choose Create New Surface. The Create New Surface dialog will pop up. Click the OK

button to create a default planar surface. This surface is, by default, located at the origin of thecustom element; if we were building a more complex custom element, we would move thesurface relative to the custom element's origin.

Go to the tree view and click the + sign on the Elem 1 icon to see the surface. You willalso probably want to click in the Visualization view, then go to the main menu and select 3DViewView All as we did earlier.

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FRED


We have an image surface and can raytrace to it, but we cannot do any analyses yet,such as spot diagrams. To perform any image analyses, we must first create an analysissurface and place this analysis surface on the image surface (note that we can have multipleanalysis surfaces in the lens system).

To create an analysis surface, rightclick on the Analysis Surfaces folder and select NewAnalysis Surface" in the tree view. We will be selecting default values for the analysissurface, so click the OK button on the dialog that appears. Then expand the Analysis folder inthe system tree view by clicking on its + sign.

Next we attach the analysis surface to Surf 1. Make sure that both Analysis 1 andSurf 1 are visible in the tree, then drag Analysis 1 and drop it on Surf 1.


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Now we can generate the spot diagram. Go to the main menu and select Analyses Positions Spot Diagram . The Positions Spot Diagram dialog will pop up. In the Pre-

Analysis Ray Operations area, check the Delete old rays and create all active sources,Raytrace all active rays, and Plot the rays as they are being raytraced checkboxes. Clickthe OK button.

The diagram that appears is a simple Position Spot Diagram.

You may want to experiment with the source definition by increasing the number of raysthat are traced and generating the spot diagram again. Rightclick on Source 1 in the treeview and select View/Edit Simplified Optical Source. If you are running the demo version,you are limited to 25 coherent rays and 500 incoherent rays.

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The Elliptical Reflector Tutorial

This tutorial will create an elliptical reflector, a volume emitting source, and an image planewith an analysis surface. The finished model is as shown below.

Elliptical

reflector

Imageplane withanalysissurface

Volume

source

To help see how the rays are tracing, we will have the rays start from the source in red,

and make any rays which reflect off the reflector be green. This is a useful feature of FRED to help identify what is happening to the rays in the model. This is shown below.

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The first step is to create the Elliptical Reflector. Start FRED up (if needed) and start a

new FRED file by using the menu item File New FRED type. Now we will create thesurface that defines the elliptical reflector geometry. Rightclick on the Geometry Folder andselect the Create New Custom Element menu selection.

FRED


After leftclicking on the Create New Custom Element menu item a dialog box will appear.Type in "Reflector" for the Name and "elliptical reflector" for the description. Click OK.


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Now expand the Geometry node (click on the "+" sign) to see the icon for the reflector wejust created. We need to add the mirror surface to this reflector. Rightclick on the Reflectorcustom element icon to pop up the dialog containing the Create New Surface option to definethe elliptical reflector.

Give this surface the name "mirror surface". Click the Down Arrow next to the Type: dialog

bar and select the Conic Foci type as shown below.

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After selecting the conic foci type you will then be able to enter the two foci points, z=1and z=5 for the first and second focus points as shown. Set the Point on the surface at z=0.Make sure you select the Ellipsoid surface type as shown.

Now leftmouse click on the Aperture tab and enter the aperture information as shownbelow. Click Apply to enter the information input so far, but keep the dialog box open.

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What Are Coatings?

Each FRED surface has a coating definition applied to it. The coating definition tellsFRED what fraction of the incident ray power (flux) is transmitted, reflected, and/or absorbedeach time a ray intersects with that surface.

What are RayTrace Controls?

When a ray hits a surface it is automatically split into reflected and transmittedcomponents. You can choose which component is raytraced (or both) by editing the RaytraceProperties. The energy of the transmitted or reflected ray is determined by the Coatingproperties. Thus, the combination of the two, coatings and raytrace properties, determineswhat happens to rays hitting the surface where they go and how much energy they carry.

Default Coating Definitions

By default, FRED loads a number of coatings into every new FRED document. You can

view those default coatings by expanding the coatings node. The Bare Substrate coatingcalculates the reflection and transmission coefficients based on the index of refraction of thematerial as if there was no coating on the material.

We want a reflective mirror. Under Coating, select "Reflect" and click Assign. UnderRaytrace Control select "Reflect Specular" and click Assign. Further, we want any ray thatintersects the elliptical reflector to change its color from whatever default value the ray has togreen by changing the Ray Colors as shown below. When we are done making these changesclick the Apply button to accept all the information we have supplied up till now. The Applybutton creates the reflector with the input that we have currently supplied. It still leaves the EditSurface dialog box up for further editing.

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The view of the elliptical reflector looks "chunky." The internal representation is, of course,smooth, but the rendering of the surface depends on the size of the triangles used to build thepicture. To improve the visualization of the elliptical reflector, go to the Visualization tab in theEdit Surface dialog. Change the drawing mode to "Surface with smooth shading" and set theTessellation to 0.25 for the X, Y and Z values.

The tessellation value determines the how finely FRED samples the surface for

rendering. The smaller the scale, the finer the sampling; this also increases the amount of timeit takes FRED to render the surface.

The finished mirror is shown below, finely smooth tessellated with the system treeinformation correctly entered.

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Now we need to create a surface to catch the reflected rays. We need once again tocreate a planar surface. First, create a new custom element.

Next we need to create the information about the custom element. Enter "Output Plane"for the Name and "plane" for the Description as shown. Then click on the OK button to acceptthis information.

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After entering the custom element information, rightclick on the created custom elementand select the option to create a new surface. The dialog box below should appear. EnterOutput Plane for the name and select Plane for the surface type as shown below.

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Enter the information on the Aperture tab as shown. Make sure that you select the Boxsha

pe for the trimming surface boundary. Click on the OK button to save this surface afterentering the Aperture data.


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Now we can move the output plane into place. To do this, go to the system tree and rightclick on the Output plane custom element. A dialog box will pop up; select thePosition/Orientation selection.

When the Location box appears. Rightclick anywhere on the Geometry location box andclick

on the Append option. Select the Shift action and then enter 10 in the Z box of this dialogas shown. This moves the output plane to the Z=10 position.

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Now we can create the volume source. To do this go to the Optical Source Folder, rightclick on the folder, and select the Create New Detailed Optical Source option.

Next enter the name Spherical volume emitter" and the description Sphere for oursource under the Source tab as shown below.

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Click on the Positions/Direction tab and select "Random Volume" for the Ray PositionType. This source type creates random points arranged throughout a volume. Enter 10000 forthe number or rays and 0.025 for the X, Y and Z semi-apertures. Finally, specify Spheroid forthe shape of the volume as shown below. For the Ray Directions portion of the window,specify "Random directions into a sphere" and 1 ray from each ray position.

Finally, go to the wavelengths tab and specify the ray color and wavelength for thissource. All rays traced for this analysis will be Red as shown below.

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Each object (and surface) needs to be located somewhere, and, most importantly, relativeto some coordinate system. Up to now we have entered objects relative to the globalcoordinate system origin, which is referred to as "Geometry." However, an object can belocated relative to any object or relative to any surface on any object. In this case, we want tolocate the source 1 mm from the mirror surface of the elliptical reflector, which corresponds toone of its foci.

To do this, we leftclick in the "Starting coordinate system" section of the dialog box. Thisbrings up a list of possible coordinate systems in which to locate the current object. Select theentry labeled "Geometry.Reflector.mirror surface ()". The empty parentheses indicate thissurface was given a name ("mirror surface"), but was not given a description. Note thehierarchy the entry Reflector is relative to the Geometry, and the surface "mirror surface" isrelative to the Reflector element.

Now right click anywhere on the Geometry.Reflector.mirror surface area and select"append". Enter a Shift in Z axis of 1 as shown in the figure on the next page.

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Looking at the system we can now see the volume source inside the reflector as shownbelow.

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Now that the system is correctly setup, we can non-sequentially raytrace our volumesource. There are four possible paths for the rays to take: (1) outward from the source to theoutput plane, (2) outward from the source but missing the output plane, (3), hitting the reflectorand then the output plane, and (4) hitting the reflector but missing the output plane. All fourpaths are traced automatically, and are shown in the figure below.

This is where our foresight in coding the rays helps. Rays which are emitted from thesource are in red. Rays from the source which hit the reflector are changed to green. Thus, itis easy to see which rays have hit the reflector and which do not.

To perform the raytrace, go to the Raytrace menu and select the Trace and Render menuitem. Shown below is a Y-Z profile of the system with the rays traced. Notice that rays directlyfrom the source are red and the reflected rays are green. An ellipse can give a perfect imageat its foci, but the source is not a point source but a small volume around the close focus, sothe image at the other focus is not perfect.

It is beyond the scope of this Test Flightto show it, but you can haveFRED

keep trackof each of the four ray paths described above, and have FRED just show a particular path ofinterest. This is extremely useful in stray light analyses, for example.

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To visualize just the ray positions on the output plane and reflector, go to the Analysesmenu and select the Visualization 3D Spot diagram. The figure below shows where the rays hitthe output plane.

Notice that you not only see ray positions on the output plane but you will also see rays that

intersected the reflector and did not hit any other surface. FRED remembers where the rays lastintersected a surface as this ray position plot shows. The figure below shows the rays at their finalintersection points, whether they are on the reflector or the output plane. Note that it is easy tosee which part of the reflector reflects to the output plane, and which part of the reflector reflectsrays which do not get to the output plane.

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To do an irradiance map of the spot diagram we need to create an analysis surface. Rightclick on the Analysis Surface folder and select the option to create a New Analysis Surface. Enter"Irradiance Calculation" for the Name of this particular analysis surface. Click on the OK button toaccept the defaults and create the analysis surface.

Now drag the analysis surface on top of the Output plane custom element icon. Then go tothe Analyses menu and select the Irradiance Spread Function menu item. You should now seethe irradiance map shown on the next page. This figure shows a white background; by default

FRED creates a black background. The default is a four-pane graphical description; for this

example, we have selected to only show three panes. This is selected under Tools Preferences; select the Miscellaneous tab, and check the box for "Use 3-pane analysis plotwindows". Uncheck the box to see all four panes.

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To change color or other plot options just right click anywhere on the screen. The menubelow will appear. To change the background color just go to the chart color and change thebackground color to white. If you wish to turn off the perspective view just left mouse click onceon the Perspective View option. This will delete the check mark in front of this option and change

the view as requested.

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More Sample Systems

After running FRED , click on the menu item FileOpen to work with one of the FRED

sample files. There are over 100 example files included with your FRED CD. If all defaults wereaccepted during installation, the Sample files can be found in C:\PROGRAM FILES\PHOTON

ENGINEERING\FRED

5.xx\SAMPLES area. These files include both imaging andilluminations systems. If you are running the demo version, the sample files can be edited, but thechanges cannot be saved and you will be limited to 500 rays or 25 coherent beams. The samplefiles themselves have a general file comment that details what each sample file does and how to

run the file in FRED . To read the file comment, click on the menu item Edit General FileComment and a dialogue window appears with this information. The sample file area is broken

up into 20 different subdirectories which are descriptive of FRED files in that directory.

Subdirectory-------------------------------------------Complete SystemsData -Eye Models

InterferometryLCD ProjectorLEDsLensesLightPipesMiscellaneousPrismsPST Calculation FilesScriptsSimple GeometrySTEPSubmitted by UsersTelescopes

ThermalTrue ColorTutorial FilesUnusual Sources

More Online Tutorials

The Online Help in FRED contains detailed tutorials that provide step-by-step instructionsfor running a total of 7 tutorials. To view or print these tutorial documents, simply go to the Helpmenu, and then go to Help/Help Topics. After you are in Help/Help Topics, click on the Contentstab; double-click on the Tutorials Folder.

You will see a list of 7 tutorials; three of these tutorials are including in this QuickStartmanual.

FRED Introductory Description (This tutorial provides you with step-by-step

instructions for creating a new system in FRED , tracing the rays, and then creating aSpots Diagram. The ray trace in the demo version is limited to 500 for an illuminationssystem (incoherent source) and 25 rays for a coherent source. The resulting analysescharts will not be indicative of true analysis results due to the limited ray trace available inthe demo version.)

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User Interface Tutorial

Cassegrain Telescope Objective Tutorial

Creating a Diffractive Optical Element Tutorial

Fiber Coupling Efficiency Tutorial

Back Scatter Tutorial

Scripting Tutorial

Search Utility

The FRED Help menu includes a keyword search under Help/Help Topics/Index tab and

also Help/Help Topics/Search tab. While the search contains most features of FRED , it is not

complete since we are actively expanding the capabilities of FRED and we are continuing to

update the Index and Search tabs to include all new and expanded features of FRED . Pleasecontact us if you search for a term that isnt found.

Getting Started on Your Own

FRED software includes lens catalogs, glass catalogs, and prism catalogs which can beeasily included when creating or appending the system geometry. Custom lenses and prisms are

easy to generate in FRED . Also, FRED can import files from Zemax, CODE V, OSLO, ASAP,and CAD systems via File Import.

You may wish to start with the Cassegrain file since there is a corresponding step-by-step

tutorial (see FRED Help Menu.) You can edit the FRED Cassegrainfile, run ray traces (up to500 rays in the demo version) and perform analyses.

After you Open an existing file, you can viewthe system from different angles by dragging

it while holding down the left mouse button. You can zoom in and out with the wheel on yourmouse.

To run a ray trace, go to the main menu bar to Ray Traceand then select Trace and Render,or use the icons on the toolbar. Various graphical analyses can be run from theAnalysismenu orfrom the buttons on the toolbar. For more in-depth information, please refer to the TUTORIALS in

the FRED /HELP Menu.

New files can be created or imported into FRED from other codes and from CADprogramssuch as Pro/Engineer, AutoCAD, Rhino, SolidWorks, Maple, CATIA, Euclid, and others. We haveone of the best and most complete CAD import/export translators available, and our clientsworldwide are extremely pleased with its capabilities. For CAD systems, the files should beexported from your CAD program in surface or solid-based IGESor STEPCAD format. Please

contact us if there are any questions. When importing CAD files, please contact us with anyquestions regarding method or supported entities.

Thank you for trying our FRED Optical Engineering Software program!As our clientsworldwide already know, we gladly provide expert technical assistance during any evaluationperiod and after your purchase. If you have any questions during your evaluation, please do nothesitate to contact our technical support personnel at [email protected] look forward

to your questions and comments regarding FRED .

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Sample FREDApplications and Outputs

FRED


LightpipesBacklights

SpectrometersLaser Systems

Biomedical ApplicationsLight and lamp sourcesMasked Lightpipes

Classic Lens Systems Fringe Outputs Light Engines


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Integrating Spheres Telescope Systems Solar Collection Systems

Fiber systems Illumination System

Color Outputs Defense Systems Multiple Color Source Analysis

Visualization in Lightpipe Systems Lighting Systems

FRED Test Flight

Documents

Transcript of FRED Test Flight