Compact On-Chip crystalline Resonator Integration with Etching Tapered Fiber Waveguide

TL;DR

This paper presents a novel chemical etching technique to integrate high-Q crystalline resonators on-chip with a tapered fiber waveguide, achieving low optical loss and active temperature tuning.

Contribution

It introduces a miniaturized tapered fiber fabrication method on silicon and demonstrates active temperature control for on-chip crystalline resonators.

Findings

Optical loss of 0.1 dB/mm achieved

Q factor exceeds 10^8 for on-chip resonators

Temperature response of 18 pm/K matches theoretical predictions

Abstract

Whispering-gallery mode crystalline resonators currently maintain the best quality factor (Q) record, however, compact on-chip packaging is still a challenge although various coupling architectures have been developed. Here, a chemical etching method is proposed to fabricate a miniaturized tapered fiber waveguide on silicon substrate. The Marangoni effect is implemented to reduce the surface roughness of the cone region. The optical loss of 0.1 dB/mm is obtained, and the Q of on-chip crystalline resonator exceeds 108. Additionally, TEC is implanted in the package to actively customize the temperature, and the temperature response of 18 pm/K is consistent with the theoretical calculation.