Towards on-chip mid infrared photonic aerosol spectroscopy

Abstract

We propose an on-chip mid-infrared (MIR) photonic spectroscopy platform for aerosol characterization to obtain highly discriminatory information on the chemistry of aerosol particles. Sensing of aerosols is crucial for various environmental, climactic, warfare threat detection, and pulmonary healthcare applications. Currently, chemical characterization of aerosols is performed using FTIR spectroscopy yielding chemical fingerprinting because most of the vibrational and rotational transitions of chemical molecules fall in the MIR range; and Raman spectroscopy. Both techniques use free space bench-top geometries.Here, we propose miniaturized on-chip MIR photonics-based aerosol spectroscopy consisting of a broadband spiral-waveguide sensor that significantly enhances particle-light interaction to improve sensitivity. The spiral waveguides are made of a chalcogenide glass material (Ge23Sb7S70) which shows a broad transparency over IR range. We demonstrate the sensing of Nmethyl aniline-based aerosol particles with the device. We anticipate that the sensor will readily complement existing photonic resonator-based particle sizing and counting techniques to develop a unified framework for on-chip integrated photonic aerosol spectroscopy.

Progress of infrared guided-wave nanophotonic sensors and devices

“…It features the on-chip integration of lasers, spiral sensors, and photodetectors. An add/ drop filter was employed for wavelength sweeping [150]. The diamond possesses a wide transparency window in the MIR and a strong chemical and physical stability.…”

“…e Aluminum nitride-on-borosilicate (Reproduced with permission from [149]). f Chalcogenide-on-insulator (Reproduced with permission from [150]). g Diamond-on-insulator (Reproduced with permission from [151]).…”

The Effect of Haematocrit on Measurement of the Mid-Infrared Refractive Index of Plasma in Whole Blood

“…These methods have been applied to a broad variety of sensing applications. Gas sensing applications include aerosol [ 9 ], methane [ 10 ], and carbon dioxide [ 11 ] detection. Biological applications include protein characterisation [ 12 , 13 ] and biofilm analysis [ 14 ].…”

A Nonclinical Spectroscopic Approach for Diagnosing Covid-19: A Concise Perspective

“…From the identity of their absorption and emission bands, it can be possible to fi nd the extent of infection. The consistency of different vibrational and rotational modes in bioaerosols (like coronavirus) is detectable in the presence of a light-sensitive material [34]. Even smart phone-assisted electrochemical signaling can help in the detection [35].…”