This blog article provides a general overview of the Prepare for OpticsBuilder tool within Opticstudio 20.1 and higher. The Prepare for OpticsBuilder tool converts OpticStudio lens files (.ZMX, .ZAR and .ZOS files) to the format used by OpticsBuilder (ZBD files). This enables the optical engineer to package their design in a format that is easily accessible from within an OpticsBuilder-supported CAD program.

Introduction

Prepare for OpticsBuilder makes the handoff between optical and mechanical engineers more efficient by enabling a simple conversion from an OpticStudio model to an OpticsBuilder (ZBD) file. The simple conversion process has three steps: User Inputs, Drawing Inputs, and Save .ZBD File.

Prepare for OpticsBuilder overview

The Prepare for OpticsBuilder tool is located in the File...Convert section of OpticStudio. 

Tip: If you do not see the Prepare for OpticsBuilder button, you will need to upgrade to OpticStudio 20.1 or higher.

Prepare for OpticsBuilder has three setting tabs to match each step of the conversion process. The "User Inputs" tab enables optical engineers to set up their analysis preferences and define the allowable deltas for Spot Size, Beam Clipping, and Image Contamination when comparing OpticsBuilder ray trace results. The allowable delta for Spot Size is also the maximum Spot Size change allowed for a successful sequential to non-sequential model conversion. See section "Error 1: Spot sizes do not match" for more information. The "Drawing Inputs" tab allows for population of the information required to automatically generate an ISO 10110 optical drawing in OpticsBuilder. Finally, the "Save .ZBD File" tab allows you to input a message for your CAD user and saves the converted file with the updated analysis settings.

The Prepare for OpticsBuilder tool includes the ability to:

• Convert a file from Sequential to Non-Sequential Mode. For this purpose, Prepare for OpticsBuilder will:

• Convert sequential surfaces to matching non-sequential geometry objects

• Check to make sure rays are positioned correctly following conversion

• Check to make sure rays are angled correctly following conversion

• Confirm that spot size change has remained below an allowable value following conversion

• Allow the user to open and inspect the non-sequential file after an unsuccessful conversion from sequential mode

• Validate that a given non-sequential object is supported in OpticsBuilder and is able to be exported

• Generate a static critical boundary ray set for sequential designs

• Manual population of drawing data for singlets, cemented doublets, triplets, and quadruplets

• Add comments to a ZBD file for other engineers to reference

• Choose whether to enable scattering and/or ray splitting in the dynamic ray trace analysis

• Define the aperture for OpticsBuilder to generate chief rays

• Add allowable deltas to OpticsBuilder as design acceptance criteria

To perform the steps above, the Prepare for OpticsBuilder tool will make a copy of the initial file. Then, if the file is sequential, the Design Lockdown tool will be run, a Static Critical Rayset will be generated, and a non-sequential conversion will be applied. This is a similar process to the one used by the Convert to NSC Group tool. There is more information on each of these steps in the Help Systems file "The Tolerance Tab...Production Tools Group...Design Lockdown", "The Tolerance Tab...Production Tools Group...Critical Rayset Generator", and "The File Tab...Convert Group...Convert to NSC Group."

Once complete, the two files will be compared. First, the rotation and offset matrices will be pulled and compared. Then, a ray trace will be run in the non-sequential file one field at a time. The detector data is stored and compared to the spot size data from the sequential file as provided by the Geometric Image Analysis tool. The tool will have the following settings:

The tool will loop through each field. For each field, the pixel size will be determined by the number of X-direction pixels on the detector in the non-sequential model. The image size will be given by multiplying the X-Half Width of the detector by 2. 

Finally, the Static Critical Rayset will be loaded into the non-sequential file and the ray landing coordinates will be read from the detector. These coordinates will be compared to the original sequential file and any change will be compared to the settings entered by the user in the "User Inputs" dialog. 

If the file is non-sequential, Prepare for OpticsBuilder will check for incompatible objects and will run a ray trace to compare the initial file to the copied file. The ray trace is saved, and a Path Analysis is performed to locate the position of the detector.

The Prepare for OpticsBuilder tool will accept focal and afocal systems.

Steps for using Prepare for OpticsBuilder

The Prepare for OpticsBuilder tool may be accessed in Sequential or Non-Sequential Mode. To use it, open the file you would like to share and navigate to File...Prepare for OpticsBuilder. You will find yourself at the "User Inputs" tab. At this point, you will:

1. Currently, Creo is the only CAD software into which the ZBD file can be loaded. If the Read-only checkbox is selected the optical data cannot be edited using OpticsBuilder, however changes can be made using CAD tools. You may choose the amount of allowable change in the location and angle of the critical rays. Position Tolerance represents the maximum allowed difference between a ray's landing position in the original file, and in the copied file. The Angle Tolerance will represent the maximum allowed angle between the target ray's vector, and the actual ray's vector. If the file is Sequential you may want to have the STOP surface as an annulus object in the CAD environment by selecting the Convert STOP Surface to Hard Aperture checkbox. If the file is non-sequential you need to select the Stop Surface/Object from the drop-down menu in Pupil Definition.

   

2. Choose the number of analysis rays used during the preparation process (if the file is sequential) and select the analysis preferences and allowable deltas. Here, you may choose whether to consider scattering or ray splitting in the ray trace. Additionally, you may also define the amount of change that is allowed on the image plane following the change in file formats. In particular, the "Spot Size" allowable delta will be used to define the acceptable change in spot size that may occur when the file is converted from Sequential to Non-Sequential Mode.  

3. Click Prepare. At this point, the tool will parse the file to make sure there are no errors or invalid object types. If starting with a sequential design, this is the step where the design is converted into a nonsequential design to be used in OpticsBuilder.

If the ZBD file creation is successful, the user may move on to the "Drawing Inputs" tab by clicking Next. If ZBD file creation is unsuccessful, an error message is displayed indicating why the process failed and steps the user may use to fix issues.

The "Drawing Inputs" tab is where the user inputs drawing data for automatic generation of ISO 10110 optical manufacturing drawings in your CAD platform. OpticsBuilder users may also setup a map of this information onto their own custom drawing template for CAD. This will then allow the information to autopopulate onto their own template every time they use the Drawing feature in OpticsBuilder.

Each lens surface pair is represented by a labeled tab at the top of the screen. If an element type is chosen to be other than singlet, a tab is created after that element to specify cement properties.

For sequential models, the following information is automatically populated on the "Drawing Inputs" tab.

• Front and back surface radii of curvature

• Front and back surface clear aperture

• Lens material

• Index of refraction

• Abbe number

• Center thickness

• Reference Wavelength

This data is pulled from the Lens and Tolerance Data Editors. Other data fields must be entered manually. All data in the Drawing Inputs tabs may be edited during this step.

For non-sequential models, the following information is automatically populated on the "Drawing Inputs" tab:

• Lens material

After populating drawing inputs the user should select Next to go to the "Save .ZBD File" tab to enter notes. These notes will be attached to the generated file and will be visible to the CAD user upon importing the file. When the user is ready to create a ZBD file they should click Save.

ZBD file format

The ZBD file format used by OpticsBuilder is intended to carry all necessary information needed for an iterative optomechanical packaging analysis; thus, allowing easy back-and-forth exchange between OpticStudio and a supported CAD program. This file type may be opened in OpticsBuilder and in OpticStudio 20.1 or later. The information within a ZBD file includes:

• Sequential model (if applicable)

• Non-sequential model

• OpticStudio ray trace baseline results

• Static critical ray bundle (sequential models only)

• Material properties

• Allowable deltas for RMS spot size, beam clipping, and image contamination

• Optical drawing information

• Optical tolerancing values

• Any exported mechanical CAD parts

When the ZBD file is opened in OpticStudio, the user may choose to open the original sequential design or a ZAR containing the non-sequential model and any additional mechanical components exported from OpticsBuilder. If the design originated in nonsequential mode and a sequential model is not present, the nonsequential ZAR will open automatically.

To read the full knowledgebase article click here.

To try out OpticsBuilder capabilities for yourself, download a free trial here.

Authors: 
Jacob Hart
Alexandra Culler, Senior Application Engineer, Ansys a Zemax Company