Relief gratings on Er/Yb-doped borosilicate glasses and waveguides by excimer laser ablation

Relief gratings have been fabricated on Er/Yb-doped borosilicate glass subs trates by laser ablation using a 193 nm excimer laser and a modified Mach-Z ehnder interferometer. The grating fabrication process was quantified using diffraction efficiency measurements and related to the incident energy den sity. Diffraction efficiencies and grating profiles are presented for grati ngs fabricated using different pulse energy densities and number of pulses, and optimised fabrication conditions are proposed. Finally, relief grating s were applied to ion-exchanged channel waveguides and spectral transmissio n measurements are presented. (C) 2000 Elsevier Science B.V. All rights res erved.