Planar waveguide structure formed on Nd:YVO4 by Kr8+ ion irradiation at ultralow fluences

We report on the fabrication of a planar waveguide structure on Nd:YVO4 laser crystal. The waveguide structure was formed by Kr8+ ion irradiation with energy of 30 MeV at fluences of 2 × 1012 cm−2. The guiding modes of the planar waveguide were measured by the prism-coupling method at wavelengths of 633 nm and 1539 nm. The reflectivity calculation method (RCM) was used to reconstruct the refractive index profiles. Relatively large positive changes in the ordinary refractive index occur in the waveguide region. The refractive index profile of the planar waveguide was a typical “well” + “barrier” distribution, and we used the finite-difference beam propagation method (FD-BPM) to simulate light propagation in the waveguide. Using the Stopping and Range of Ions in Matter (SRIM 2008) software, the energy loss during ion irradiation was simulated to obtain a better understanding of the formation of the waveguide structure. The investigation of the absorption bands demonstrated that the transmission properties of the bulk Nd:YVO4 crystal have been preserved after ion irradiation.