Did you know TracePro is an invaluable tool for analyzing and mitigating light guide crosstalk?
Light guides are an important part of many types of devices. Light guides move light from one point to another. The light source could be an LED, or any other type of source. The other end of the light guide could be a display or indicator or some type of sensor. A fiber optic cable is another example of a light guide.
One type of indicator uses a series of light guides arranged sequentially in a row or circular pattern. This can be used to display information such as power levels or status conditions. Each light guide in this type of light guide array will have its own light source. The light sources can be turned on one at a time, or in multiples. One potential problem in these applications is light guide crosstalk. Crosstalk is when light from one light guide leaks into another light guide, potentially causing an incorrect or misleading display.
From an optical design point of view, a light guide array would be constructed of optically isolated light guides that prevent the possibility of crosstalk. This is ideal from an optical point of view but could be problematic from a mechanical and assembly perspective. Each light guide would need to be mounted and aligned individually. One alternative is to mold the light guide array as a single assembly, with mechanical connections between the light guides to facilitate mounting and alignment. It is these mechanical connections that can lead to crosstalk.
TracePro has the tools that are essential to identify the paths light can take to get from one light guide to another. This could be an adjacent light guide or one further along the array. The Path Sort Table can show all of the paths that rays can take from a source to other light guide exit surfaces. The Path Sort Table can be used with the Irradiance/Illuminance Map to show the distribution, total flux, and irradiance/illuminance values on each light guide exit surface.
The Photorealistic Rendering and Luminance plots in TracePro can show the effects of any crosstalk as they would be seen by a viewer or a luminance camera. Results can be shown qualitatively or quantitatively.
If crosstalk is identified, changes to the light guide array can be made to reduce crosstalk. Changing the size and or shape of the light guide connecting structure and the updated design tested in TracePro. This process can be iterated until the crosstalk is at an acceptable level.
TracePro gives light guide designers the tools they need to identify and mitigate crosstalk in light guide arrays.