Characterization of a multilevel micro/nano-plastics Infrared Spectroscopy using optical chopper modulation and induced anti-stokes shift techniques

Abstract

This paper explores the provision of an all-in-one IR-spectroscopy platform for nanoplastics as well as less than 10$\mu$ m microplastics size, aiming to surpass the current limit of $20\mu m$. For such a multilevel spectroscopy, we propose an optical chopper configuration that produces multilevel modulation of laser source, and an induced anti-Stokes shift technique that adds energy in a sample assumed to contain microplastics, their degraded form, and their possible retention. We control reduction of the source energy flux using a splitter, and a linear edges’ chopper, whose windows alternate between empty and filled with a transmitting but high absorbance nanotube material spaces, while controlling the sample emission using an induced Anti-Stokes shift. This yields two methods: vibrational/rotational and electronic transitions. The first method provides us with the absorbance against energy of a sample assumed to contain compounds made of CC, CH, CO, CN, xH. The second method defines the set of lower bandpass of the assumed diffraction grating entry from the wavelengths emitted, from where the bandpass are derived. The new geometrical chopper’s configuration, and its transmitted signals for a flux distribution are given. The IR source energy and the induced hot-band, both suitable for the multilevel bandpass for the detection of nano/micro-plastics and their retained nanoparticles spectroscopy are discussed. We obtain bandpass by scaling down the wavelengths which vary only when both energy sources vary for any allowed atomic energy level, and we characterize the absorbance of nanoparticles components in near-IR region.