You’re not too far off. There’s for example the Quantis random number generator, which uses photons:

https://www.idquantique.com/random-number-generation/product...

From the brochure:

“ Photons - light particles - are sent one by one onto a semi-transparent mirror and detected. The exclusive events (reflection - transmission) are associated to « 0 » - « 1 » bit values.”