Preservation of fluorescence and Raman gain in the buried channel waveguides in neodymium-doped KGd(WO4)2(Nd:KGW) by femtosecond laser writing.

We report on the preservation of fluorescence and Raman gain in low-repetition-rate femtosecond laser written buried channel waveguides in neodymium-doped KGd(WO4)2. The propagation loss index, profile reconstruction, and calculation of the modal intensity distribution by the beam propagation method of the waveguide are presented. Microluminescence spectra of the waveguides show that the fluorescence properties of Nd3+ ions are not significantly affected by the waveguide formation processing, which indicates a fairly good potential for further laser actions in a compact device. Micro-Raman spectra are also performed to reveal the preservation of the characteristic 768 and 901 cm-1 Raman mode intensities in the guiding regions.