Work

Thermorefractive stable tantalum pentoxide microring resonator for dual-polarization four-wave mixing spectral translation

Year: 2025

Type: article

Abstract: Integrated tantalum pentoxide (Ta 2 O 5 ) photonics has emerged as a promising platform for nonlinear optical applications due to its high Kerr nonlinearity, low propagation loss, CMOS compatibility, and exceptionally low thermo-optic coefficient. In this work, we demonstrate, for the first time, dual-polarization four-wave mixing (FWM) spectral translation in a Ta 2 O 5 microring resonator. The device features a trapezoidal waveguide geometry optimized to support both TE 00 and TM 00 fundamental modes with intersecting dispersion curves at 1548 nm. The fabricated resonator exhibits high loaded quality factors of 1.78 × 10 5 (TE 00 ) and 1.46 × 10 5 (TM 00 ), and low propagation losses of 1.85 dB/cm and 1.96 dB/cm, respectively. The device also shows excellent thermorefractive stability, with temperature-dependent wavelength shifts (TDWS) as low as 7.19 pm/K (TE 00 ) and 7.49 pm/K (TM 00 ). The difference of the TDWS enables accurate resonance alignment via chip temperature tuning. Under on-chip pump powers of 14.13 dBm (TE 00 ) and 13.87 dBm (TM 00 ), FWM conversion efficiencies of –36.15 dB and –35.29 dB are achieved at the same pump wavelength. These results underscore the potential of Ta 2 O 5 for doubling spectral capacity, including polarization-multiplexed optical communication and dual-comb generation for spectroscopy.

Source: Optics Express

DOI: 10.1364/oe.578565