LightTools Enewsletter

May 2017

Quick Tip: Linking PSA and Configurations

LightTools 8.5 includes an enhanced version of the Parameter Sensitivity Utility, now called the Parameter Sensitivity Analyzer (PSA). This updated tool provides many new analysis features, an improved user interface, captures of more data types, and new data transfer options with Microsoft Excel. PSA is accessible in the Optimization > Parameter Sensitivity menu. The following training presentation on the Customer Support Portal provides various examples with step-by-step instructions and test models.

Highlighted in this tip is the ability to interchange the data between PSA and Configurations. Configurations, first introduced in LightTools 8.4, provide a way to include multiple values for a given set of model parameters, and switch between different configurations using a single drop-down menu.

PSA and Configurations with Numeric and Non-Numeric Parameters Example

Consider the LED collimator shown below, with two different LED source options.

LED collimator

Assume we want to compare two different LED options, and how output changes between different Lens Y and Lens Z coordinates. This is like studying the sensitivity of the system performance as a function of LED position and the LED itself.

To accomplish this with PSA, we can use PSA in Configuration mode. This requires each variable state to be evaluated as a separate configuration. PSA scans through each configuration, and conducts an evaluation and records the results. This can be a bit tedious to set up manually, especially for runs with many variable trial states (in our case, we have 18 total states to evaluate). Fortunately, you can use PSA to shorten the process by generating a list of the numeric variable values that can then be copied into the Configuration Manager.

In PSA, it is simple to add the Y and Z position as variables and generate a parameter scan list.

parameter scan list

The following picture shows the variable states in PSA. Y will range from 0 to 1 in 3 steps. Z will range from -0.5 and 0.5 in 3 steps. In all, there are 9 combinations. A table shows the variable value for each trial.

variable states in PSA

Once the variable states are generated in PSA, you can convert each trial into a different configuration. To add these configurations:

1. In the property window for the lens’ coordinates, select the numeric field for Y. 

2. Right-click and select Add Configuration Item. You need to do this step two times, once for each coordinate (Y, and Z). 

Add Configuration Item

3. After adding the configuration items, go to Edit > Configurations. Newly added items will appear as Y_1, and Z_1. You can rename these items. The required number of configurations is 18 [(2 LEDs) x (3 Y positions) x (3 Z positions)].

4. For each LED, go to the LED’s Properties > Display tab and make the Visible control a configuration item. On each source’s Emittance tab, make the Enabled control a configuration item. This will add four additional configuration items. Note that these are non-numeric settings for the source. In the Configuration Manager, they appear as checkboxes:

configuration item

5. Back in PSA, copy the Y and Z variable values generated by the Uniform_Grid PSA mode. Use Ctrl+C to copy data from the grid or right-click and select Copy Grid Values to Clipboard.

Parameter Sensitivity Analyzer

6. Paste the values in Excel twice, one after the other. You can name each trial (avoid spaces). The first 9 entries will be for the first LED, and the last 9 entries will be for the second LED. Enter Yes to enable the appropriate controls, and No to disable the controls per trial.

name each trial

7. Copy and paste the data from Excel to the Configuration Manager.

Configuration Manager

Once configurations are in the LightTools model, you can:

  • Switch between different configurations quickly in the dockable Configuration control panel (View > Configuration Control Panel) in the main LightTools window. You can edit the configuration items for each trial individually.
Configuration Control Panel

  • Run PSA in Configuration mode. Now you can scan the same parameters for each LED in one PSA run. In this mode, you can adjust the configuration item values to be nonuniform if you like, or choose a subset of the defined configurations to analyze.
Configuration mode

By using the PSA in a Uniform_Grid analysis mode, you can quickly generate a uniform grid of parameter settings. It becomes easy to copy this grid data into different LightTools configurations, and add non-numeric parameters like ray trace settings or even optical properties. When you have these configurations generated, it is easy to go back and evaluate them later.

LightTools 8.5 New Features Webinar Recording Available

The LightTools 8.5 New Features Overview webinar is now available on the Customer Support Portal.

View this video to see new features such as: Conformal Receivers and Enhanced Illuminance Display in the 3D Design View, the Parameter Sensitivity Analyzer, and improvements to the Light Guide Designer, Freeform Designer and Street Light Utility.

Customer Networking Reception at IODC

Tuesday, July 11
6:45 - 9:00 p.m.

Guard & Grace 
1801 California Street
Denver, CO 80202

Synopsys' Optical Solutions Group cordially invites you to an evening reception at IODC 2017. Join us for food and drinks, talk with our LightTools experts, share ideas with other users, and learn about our latest software innovations at our demo stations. Always a popular and well-attended event with our customers!

Please RSVP before July 4 if you plan to attend the reception. We hope to see you there!

LightTools User Group - Save the Date

LightTools User Group

Please save the date for our annual LightTools User Group meetings. LightTools User Group Meetings are currently planned for September 12 in Marlborough, MA; and September 19 in Sunnyvale, CA.

What topics would you like to see discussed? What features in LightTools would you like to know more about? How could we help you be more productive in LightTools? You have an opportunity to help determine the topics during the annual LightToolsUser Group meetings. We welcome all ideas and will take those into consideration as we plan for the user group meetings. Help us make the user group a truly worthwhile event for you.

Send your brilliant topic ideas to, or join our LightTools Group on LinkedIn to submit your ideas there. We look forward to hearing them!

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