Chemical Characterization of Aerosol Particles Using On-chip Photonic Cavity Enhanced Spectroscopy

TL;DR

This paper presents a novel on-chip photonic sensor using a silicon nitride resonator for chemical analysis of aerosol particles, demonstrating broad wavelength operation, high sensitivity, and accurate detection comparable to commercial spectrometers.

Contribution

Introduction of a compact, on-chip photonic cavity sensor capable of chemical characterization of aerosols with broad spectral range and high sensitivity, suitable for various remote sensing applications.

Findings

Successfully detected N-methyl aniline aerosols in NIR range.

Sensor's spectral data aligns well with commercial spectrometer results.

Device's small size benefits remote and wearable sensing applications.

Abstract

We demonstrate the chemical characterization of aerosol particles with on-chip spectroscopy using a photonic cavity enhanced silicon nitride (Si3N4) racetrack resonator-based sensor. The sensor operates over a broad and continuous wavelength range, showing cavity enhanced sensitivity at specific resonant wavelengths. Analysis of the relative change in the quality factor of the cavity resonances successfully yields the absorption spectrum of the aerosol particles deposited on the resonators. Detection of N-methyl aniline-based aerosol detection in the Near InfraRed (NIR) range of 1500 nm to 1600 nm is demonstrated. Our aerosol sensor spectral data compares favorably with that from a commercial spectrometer, indicating good accuracy. The small size of the device is advantageous in remote, environmental, medical and body-wearable sensing applications.