Damage behaviors in Nd:YVO 4 by multi-energy proton implantation

We fabricated planar waveguides in x-cut and z-cut Nd:YVO4 by multi-energy proton implantation to a total fluence of 4.5×1016ions/cm2 at room temperature. The effective refractive indices of guiding modes in the waveguide were measured by the prism-coupling method at wavelengths of 633 and 1539nm, and the refractive index profile of the waveguide were reconstructed by the reflectivity calculation method. Damage behaviors of x-cut and z-cut Nd:YVO4 waveguides after multi-energy proton implantation were investigated by the Rutherford backscattering/channeling technique and confocal micro-Raman spectra. To our knowledge, there has been no report on Rutherford backscattering/channel and Raman spectra of Nd:YVO4 waveguides formed by multi-energy proton implantation. We found that the minimum yield in the Rutherford backscattering/channeling spectra of Nd:YVO4 depends on cut direction. The minimum yield of the z-cut Nd:YVO4 virgin was 1.87%, which increased to 2.41% after proton implantation, while the minimum yield of the x-cut Nd:YVO4 virgin was 14.53%, which increased to 15.01% after proton implantation. In the Raman spectra, most of peak positions and peak widths had no obvious change before and after proton implantation.