Infrared Light bridge

I need to make a light bridge timer for a project i'm working on. I have narrowed the source in the bridge down to infrared as it is the most reliable in outdoor conditions however the light bridge has to be across a racetrack with a width of 10m and i cant seem to find any infrared light bridges with this sort of range. Any help or guidance would be much appreciated. Thanks

Search the forum (top of every page) for "beam break sensor". Leo..

For good performance under outdoor conditions you need to modulate the IR light beam, typically 38 kHz, and a corresponding detector. For long range, have focusing lenses or reflectors at one or both ends.

Or use a visible laser diode with focusing optics, which allows you to see when the emitter is accurately aligned with the detector.

There are plenty of commercial options that extend to 60 meters or more, for example http://www.sensortips.com/vision-systems/photoelectric/long-range-door-gate-photoelectric-sensors/