Second harmonic generation into the near ultraviolet in Zr-diffusion-doped lithium tantalate ridge waveguides
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2025-03-11 |
| Journal | Optics Express |
| Authors | Sergiy Suntsov, Chaitanya Sharma, Kore Hasse, Detlef Kip |
| Institutions | Helmut Schmidt University |
| Citations | 4 |
Abstract
Section titled āAbstractāWe report on the efficient second harmonic generation at a near-UV wavelength of 399.7 nm in periodically poled Zr-doped LiTaO 3 waveguides. High-temperature in-diffusion of ZrO 2 layers into congruent LiTaO 3 substrates with simultaneous improvement of crystal stoichiometry by vapor transport equilibration in a Li-rich atmosphere was performed for the fabrication of planar waveguides. This new method enables very high photorefractive damage thresholds and allows us to avoid the known disadvantages of, e.g., proton exchange or titanium in-diffusion waveguide fabrication methods, which lower resistance to photorefractive damage. Low-loss ridge waveguides were then fabricated using a diamond blade saw. At a maximum available coupled power of 540 mW of the near-infrared pump laser, 49 mW of second harmonic light was generated in a 22 mm long sample with a normalized conversion efficiency of 3.5%Ā·W -1 Ā·cm -2 , exceeding the previously reported powers for LiTaO 3 waveguides in this wavelength range. Furthermore, by heating the sample, a temperature tuning coefficient of 32 pm/Ā°C was measured for the generated second harmonic wave.