Abstract

Praseodymium-doped lithium yttrium fluoride (Pr³⁺:LiYF₄ – Pr:YLF) is a common gain crystal for solid-state lasers emitting in the visible spectral range. Its high quantum efficiency and high peak emission cross sections on the order of 10^-19 cm² allow for efficient laser operation at watt-level output power [1]. Here we report on our current activities on ion-implanted waveguides in this material. The implantation of ions induces a refractive index change in the surface region and an index barrier in the ion-stopping range of the material [2], enabling planar waveguiding. Precision diamond blade dicing is an effective method for the production of ridges on the surface of crystalline materials [3]. Combining these two methods allows for the fabrication of ridge waveguides with a high lateral index contrast. This enables stronger light confinement than in waveguides fabricated by other methods, e.g., fs-laser direct writing [4]. Ion-implanted and diced ridge waveguides in Pr:YLF are thus a promising approach for further miniaturization and integration of visible lasers with high beam quality.

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