Group-velocity dispersion engineering of tantala integrated photonics

TL;DR

This paper measures the refractive index of tantala and demonstrates its use in engineering group-velocity dispersion for integrated photonics, enabling advanced applications like supercontinuum generation and soliton microcombs.

Contribution

It provides the first detailed refractive index data for tantala and applies this data to GVD engineering in integrated photonic devices, expanding design possibilities.

Findings

Refractive index measurements of tantala across spectral ranges.

Successful GVD engineering in waveguides and resonators.

Demonstration of supercontinuum generation and potential for soliton microcombs.

Abstract

Designing integrated photonics, especially to leverage Kerr-nonlinear optics, requires accurate and precise knowledge of refractive index across the visible to infrared spectral ranges. Tantala (Ta_2O_5) is an emerging material platform for integrated photonics and nanophotonics that offers broadband ultralow loss, moderately high nonlinearity, and advantages for scalable and heterogeneous integration. We present refractive-index measurements on a thin film of tantala, and we explore the efficacy of this data for group-velocity dispersion (GVD) engineering with waveguide and ring-resonator devices. In particular, the observed spectral extent of supercontinuum generation in fabricated waveguides, and the wavelength dependence of free spectral range (FSR) in optical resonators provide a sensitive test of our integrated-photonics design process. Our work opens up new design possibilities with tantala, including with octave-spanning soliton microcombs.