Relief gratings have been fabricated on Er/Yb-doped borosilicate glass substrates by laser ablation using a 193 nm excimer laser and a modified Mach-Zehnder interferometer. The grating fabrication process was quantified using diffraction efficiency measurements and related to the incident energy density. Diffraction efficiencies and grating profiles are presented for gratings fabricated using different pulse energy densities and number of pulses, and optimised fabrication conditions are proposed. Finally, relief gratings were applied to ion-exchanged channel waveguides and spectral transmission measurements are presented.