375-395 nm UV generation in Zn-indiffused MgO-doped PPLN waveguides pumped by an Alexandrite laser

We present results of wide wavelength coverage in the ultra-violet (UV) from a Zn-indiffused MgO-doped periodically-poled lithium-niobate (PPLN) waveguide. A continuous tuning range of 375-395 nm is obtained via second-harmonic-generation (SHG) in Λ = 6.1 - 6.9 µm poled gratings using a single continuously tunable alexandrite pump laser. Detailed results of the waveguide modes are provided and are shown to match well with the theoretical model. A maximum UV power of 4.1 mW is obtained from 200 mW of throughput pump power from the third-order SHG interaction, providing a route toward a compact and rugged laser source across the 350-400 nm UV range.