Preparation and characteristics of the O³⁺-ion-implanted and femtosecond laser-ablated waveguide in the high-gain Nd³⁺-doped laser glass

In the work, the planar and ridge waveguides are fabricated by the combination of ion implantation and femtosecond laser ablation in the high-gain Nd³⁺-doped laser glass. The species, energy, and dose of ion implantation are O³⁺ ion, 6.0 × 10⁶ eV, and 5.0 × 10¹⁴ ions/cm², respectively. The pulse energy and the scanning velocity are 3 μJ and 50 μm/s for the FS laser ablation. The m-line curve and the refractive index distribution of the planar waveguide are got via a prism coupler and a reflection calculation method, respectively. The refractive index in waveguide core is increased by 2.3 × 10^–3 through the O³⁺ ion irradiation. The microscope images and near-field intensity distributions for both planar and ridge waveguides are measured by a Nikon microscope and an end-face coupling arrangement, respectively. The cross-sectional dimension of the ridge waveguide is 4.2 μm × 10 μm. It has the potential to explore new dimensions in the field of the active waveguides.