Integration of an optical fiber taper with an optical microresonator fabricated in glass by femtosecond laser 3D micromachining

TL;DR

This paper demonstrates the fabrication of a high-Q microtoroid resonator integrated with a fiber taper using femtosecond laser 3D micromachining and CO2 laser welding, enabling efficient optical coupling in a compact device.

Contribution

It introduces a novel method for integrating a fiber taper with a femtosecond laser-fabricated microresonator, maintaining high quality factors for practical optical applications.

Findings

Achieved a microtoroid resonator with a Q-factor of ~3.24x10^6.

Successfully integrated the fiber taper with the microresonator via CO2 laser welding.

Maintained a high Q-factor of 3.21x10^5 in air after assembly.

Abstract

We report on fabrication of a microtoroid resonator of a high-quality factor (i. e., Q-factor of ~3.24x10^6 measured under the critical coupling condition) using femtosecond laser three-dimensional (3D) micromachining. Coupling of light into and out of the microresonator has been realized with a fiber taper that is reliably assembled with the microtoroid. The assembly of the fiber taper to the microtoroid is achieved by welding the fiber taper onto the sidewall of the microtoroid using CO2 laser irradiation. The integrated microresonator maintains a high Q-factor of 3.21x10^5 as measured in air.