Application of narrowband optical intensity hybrid spectra filter and router device models by controlling the laser systems of laser-induced breakdown spectroscopy for lithium detection in tissue and single cells

Abstract

Laser-induced breakdown spectroscopy (LIBS) has proven to be a valuable tool for the detection and quantification of trace elements such as lithium (Li) in various matrices. This technique offers rapid, real-time and minimally invasive analysis, making it an attractive alternative to traditional techniques like inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS). However, the pulse duration of the laser, in the nanosecond (ns), picosecond (ps) or femtosecond (fs) range, significantly influences the LIBS measurement quality. In this study, we compared ns-laser, ps-laser and fs-laser systems of LIBS for the determination of Li in biological tissues and single cells with a focus on spectral intensity, peak width (particularly, FWHM), plasma temperature, electron density, limit of detection (LOD) and signal-to-noise ratio (SNR). Our findings are further applied to realize some novel device models: a narrowband optical pass spectral filter (NBOPF), a narrowband optical reject spectral filter (NBORF) and a frequency domain multiplexing (FDM) optical router. The models demonstrated significant potential for quantum communication devices, which can be achieved by the optimization of bandwidth contrast, filter gain, channel equalization ratio and contrast index. For the NBOPF and NBORF, maximum bandwidth contrasts are obtained at 96% and 98%, respectively. Maximum filter gain is found to be 3.0. For the FDM optical router, maximum channel equalization and contrast index are obtained at 85% and 81%, respectively.