Abstract: In the method for on-substrate cleaving of a sol-gel waveguide, a sol-gel buffer layer is produced on a substrate, and a first portion of the sol-gel buffer layer is masked. The second portion of the sol-gel buffer layer is exposed to UV light to make this second buffer layer portion resistant to a given solvent. A sol-gel guide layer is produced on the sol-gel buffer layer after exposure of that second buffer layer portion to UV light. Then the sol-gel guide layer is covered with a mask having an elongated slit opening presenting the general configuration of the waveguide. This elongated slit opening crosses an intersection between the first and second buffer layer portions. The masked sol-gel guide layer is exposed to UV light to form the waveguide in the sol-gel guide layer, exposure to UV light rendering the waveguide resistant to the given solvent.