Laser distance measuring

I've been pondering building a musical instrument with multiple 'strings' that are actually a set of distance measuring devices set up in a line. However in order to avoid the strings interfering with each other it occured to be lasers might be the best approach. Unfortunately pre-constructed laser range finders are pricey. Has anyone got any experience putting these together from smaller components (i.e. a laser light plus a sensor).

Alternatively I guess I could use IR range finders and put ridges in between the 'strings', but it'd make it harder to sweap your fingers across the instrument.

-chris

or any other technique

Obviously if ya can think of another technique, that’s awesome too :slight_smile: