Recent Progress on Tantalum Pentoxide Based Nonlinear Waveguides Applications
Chung-Lun Wu1*, Din-Hsin Ou1, Jen-Yang Huang1, Yi-Jen Chiu1, Min-Hsiung Shih1,3,4, Ann-Kuo Chu1, Chao-Kuei Lee1,2
1Department of Photonics, National Sun Yat-sen University, Kaohsiung, Taiwan
2Department of Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
3Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
4Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:Chung-Lun Wu,
Due to the high optical nonlinearity as well as free-carrier absorption free properties of Tantalum pentoxide (Ta2O5), it has been regarded as a suitable candidate to develop nonlinear waveguide applications. For instance, supercontinuum generations, frequency combs generation, and ultrafast all-optical switching. In this talk, we would like to go through our recent progress on the Ta2O5 based nonlinear waveguides applications. First part is the enhanced four-wave mixing (FWM) in the Ta2O5 based ring resonator. Based on a power build up characteristic of ring resonator, the FWM conversion efficiency can be significantly enhanced with the ring structure. By comparing to the FWM process in the ring cavity and channel waveguide with the same coupled power, the conversion efficiency can be enhanced up to 20 dB in the ring resonator with the Q factor of ~50000. For the second part, the waveguide dispersion issue of Ta2O5 has been analyzed by using the Mach-Zehnder interferometer (MZI) structure. The group indexes as well as the chromatic dispersion of Ta2O5 with different waveguide dimensions have been determined by analyzing the transmission spectrum of MZI structure. By precisely setting the waveguides dimensions of Ta2O5, the anomalous/normal dispersions can be engineered. Such results are critical for realizing the FWM parametric gain in Ta2O5 waveguide devices, and the possibility of achieving frequency comb generation in Ta2O5 based high Q ring resonator.

Keywords: Tantalum pentoxide, Waveguides, Nonlinear optics, Four-wave mixing, Chromatic dispersion