Trapped Rainbow Techniques for Spectroscopy on a Chip and Fluorescence Enhancement

TL;DR

This paper demonstrates broadband trapped rainbow effects in tapered nano waveguides, enabling enhanced light-matter interactions and fluorescence, with potential applications in spectroscopy and optical sensing.

Contribution

It presents the first experimental realization of broadband trapped rainbow in visible wavelengths using tapered nano waveguides, demonstrating fluorescence enhancement.

Findings

Broadband trapped rainbow observed in visible range.

Significant fluorescence enhancement due to slow light effects.

Potential for improved spectroscopy and sensing applications.

Abstract

We report on the experimental demonstration of the broadband "trapped rainbow" in the visible range using arrays of adiabatically tapered optical nano waveguides. Being a distinct case of the slow light phenomenon, the trapped rainbow effect could be applied to optical signal processing, and sensing in such applications as spectroscopy on a chip, and to providing enhanced light-matter interactions. As an example of the latter applications, we have fabricated a large area array of tapered nano-waveguides, which exhibit broadband "trapped rainbow" effect. Considerable fluorescence enhancement due to slow light behavior in the array has been observed.