Self-focused beams to couple light into a whispering-gallery mode resonator

TL;DR

This paper introduces a novel coupling method for whispering-gallery mode resonators using a prism-shaped crystal with an inscribed waveguide created by beam self-trapping, combining mode selectivity and robustness.

Contribution

It presents a new in-situ waveguide inscription technique enabling optimized light coupling into whispering-gallery mode resonators.

Findings

The method achieves high mode selectivity.

It demonstrates robust and efficient coupling.

The technique simplifies the coupling process.

Abstract

We propose an original method to couple light into a whispering-gallery mode resonator. This method benefits from the mode selectivity and robustness of the prism-coupling along with the single-mode propagation of the fiber taper. It consists in a prism shaped crystal with a waveguide inscribed inside it. The waveguide is self-inscribed in-situ by beam self-trapping to allow an optimum coupling to a given resonator.