Turbid Media Extinction Coefficient for Near-Infrared Laser Radiation

23rd International Laser Physics Workshop

Dreischuh, T.^1 ; Gurdev, L.^1 ; Vankov, O.^1 ; Stoyanov, D.^1 ; Avramov, L.^1

Institute of Electronics, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee Blvd., Sofia

1784, Bulgaria^1

关键词: Extinction coefficients;    Near infrared region;    Near-infrared lasers;    Radiation wavelength;    Scattering co-efficient;    Semi-infinite turbid media;    Spatial intensity distribution;    Wavelength dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/594/1/012030/pdf
DOI  :  10.1088/1742-6596/594/1/012030

来源: IOP

【 摘 要 】

In this work, extended investigations are performed of the extinction coefficient of Intralipid-20% dilutions in distilled water depending on the Intralipid concentration, for laser radiation wavelengths in the red and near-infrared regions covering the so-called tissue optical window. The extinction is measured by using an approach we have developed recently based on the features of the spatial intensity distribution of laser-radiation beams propagating through semi-infinite turbid media. The measurements are conducted using separately two dilution- containing plexiglass boxes of different sizes and volumes, in order to prove the appropriateness of the assumption of semi-infinite turbid medium. The experimental results for the extinction are in agreement with our previous results and with empiric formulae found by other authors concerning the wavelength dependence of the scattering coefficient of Intralipid-10% and Intralipid-20%. They are also in agreement with known data of the water absorptance. It is estimated as well that the wavelengths around 1320 nm would be advantageous for deep harmless sensing and diagnostics of tissues.