Application of Narrowband Optical Intensity Spectra Filter and Router Device models by controlling laser systems of Laser-Induced Breakdown Spectroscopy for Lithium Detection in Tissue and Single Cell

Abstract

Laser-Induced Breakdown Spectroscopy (LIBS) has proven to be a valuable tool in the detection and quantification of trace elements, such as lithium, 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) or Atomic Absorption Spectroscopy (AAS). However, the pulse duration of the laser, whether in the nanosecond (ns) or femtosecond (fs) range, significantly influences the LIBS measurement quality. In this study, we compare ns LIBS and fs LIBS for the determination of lithium (Li) in biological tissues and single cells, with a focus on spectral resolution, peak width (FWHM), background noise, spatial resolution, and reproducibility. Our results reveal that fs LIBS consistently outperforms ns LIBS in all aspects, providing enhanced sensitivity, sharper spectral features, and higher accuracy, making it the superior choice for lithium detection in single cells and biological tissues. Also, our findings are further applied to realize some novel device models, which are Narrowband Optical Pass Spectra Filter (NBOPF), Narrowband Optical Reject Spectra Filter (NBORF) and a Frequency Domain Multiplexing (FDM) optical Router. The models demonstrate significant potential for quantum communication devices, which can be achieving by optimization of bandwidth contrast, filter gain, channel equalization ratio and contrast index. For NBOPF and NBORF, maximum bandwidth contrasts are obtained 95% and 99%, respectively. Maximum filter gain is found 2.4. For FDM optical router, maximum channel equalization and contrast index are obtained 85% and 81%.