Photonic crystal resonator integrated in a microfluidic system

TL;DR

This paper presents a novel integrated optofluidic system with a photonic crystal resonator for label-free refractive index detection in microfluidic applications, demonstrating high sensitivity and real-time measurement capabilities.

Contribution

The work introduces a new integrated photonic crystal resonator within a microfluidic system fabricated on a silicon oxynitride platform, enabling sensitive, label-free detection of refractive index changes.

Findings

Maximum sensitivity of 480 nm/RIU

Refractive index range from 1.3330 to 1.3616

Linear wavelength shifts observed

Abstract

We report on a novel optofluidic system consisting of a silica-based 1D photonic crystal, integrated planar waveguides and electrically insulated fluidic channels. An array of pillars in a microfluidic channel designed for electrochromatography is used as a resonator for on-column label-free refractive index detection. The resonator was fabricated in a silicon oxynitride platform, to support electroosmotic flow, and operated at 1.55 microns. Different aqueous solutions of ethanol with refractive indices ranging from n = 1.3330 to 1.3616 were pumped into the column/resonator and the transmission spectra were recorded. Linear shifts of the resonant wavelengths yielded a maximum sensitivity of 480 nm/RIU and a minimum difference of 0.007 RIU was measured.