Effect of refractive index on the measurement of optical properties in turbid media

Abstract

Continuous-wave measurement-based methods offer a rapid cost-effective way to determine optical properties in turbid media. This method requires a measure of the refractive index of the medium, which is often unknown a priori. Whereas previous studies have reported that the refractive index has little impact on the measurement of optical properties, here we show a significant effect of refractive indices on measurements, using both simulations and experiments. In addition we propose a noniterative method to determine the refractive index of the medium. This method can also provide an optimal initial guess of the optical properties for the standard iterative method for determining optical properties in turbid media. Our method is confirmed by simulations and experiments with latex spheres and Intralipid suspensions.

Refractive index measurement of turbid media by transmission of backscattered light near the critical angle

“…When absorption by the material is small, most of the energy flux is carried by the diffuse component. The effective RI assigned to the coherent component of light has been investigated in recent years [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], and its nonlocal nature has been established [19,25]. However, as already said the effective RI seen by diffuse light has been barely investigated, and the only reference reporting efforts in the past that helps address this question is that of Meeten and North [6].…”

Determination of refractive indices of porcine skin tissues and Intralipid at eight wavelengths between 325 and 1557 nm

“…1 Limited studies have shown that refractive index can be used in modeling of tissue optics to characterize the effect of sample interfaces with ambient media on the inverse determination of bulk parameters and light distribution in heterogeneous tissues. [2][3][4] It is therefore an important task to obtain accurately the refractive index of tissues and its variation with wavelength for further improving tissue optics modeling, image reconstruction, 5 and instrumentation development.…”

Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography

“…As observed by Bartlett and Jiang [21], the chosen n value may influence μ a and ${\mu }_s^{\prime }$ estimation. This observation was obtained for a semi-infinite medium, a geometry different from the used cubic OP sample.…”