Competition Effects during Femtosecond Laser Induced Element Redistribution in Ba- and La-Migration Based Laser Written Waveguides

Fs-laser induced element redistribution (FLIER) has been a subject of intensive research in recent years. Its application to various types glasses already resulted the production efficient optical waveguides, tappers, amplifiers and lasers. Most work reported on FLIER-based waveguides refers structures produced by cross-migration alkali (Na, K) lanthanides (mostly La). The latter elements act as refractive index carrying elements. Herein, we report Ba-based, FLIER-waveguides phosphate glass with an contrast > 10?2. Phosphate modified same amount Na2O K2O, variable amounts BaO and/or La2O3 were used produce Ba or La acting carriers. Ba-only show waveguide writing threshold light guiding performance comparable that La-based structures. However, mixed Ba-La much higher migration threshold, smaller compositionally regions. This behavior is consistent competition effect both (Ba La) against alkalis. Such can be applied inhibit undesired effects fs-laser processing applications multicomponent glasses.