Continuous refractive index dispersion measurement based on derivative total reflection method

Wang

et al. 2016

J. Biomed. Opt

Self Cite

The complex refractive index dispersion (CRID), which contains the information on the refractive index dispersion and extinction coefficient spectra, is an important optical parameter of biotissue. However, it is hard to perform the CRID measurement on biotissues due to their high scattering property. Continuous CRID measurement based on internal reflection (CCRIDM-IR) is introduced. By using a lab-made apparatus, internal reflectance spectra of biotissue samples at multiple incident angles were detected, from which the continuous CRIDs were calculated based on the Fresnel formula. Results showed that in 400-to 750-nm range, hemoglobin solution has complicated dispersion and extinction coefficient spectra, while other biotissues have normal dispersion properties, and their extinction coefficients do not vary much with different wavelengths. The normal dispersion can be accurately described by several coefficients of dispersion equations (Cauchy equation, Cornu equation, and Conrady equation). To our knowledge, this is the first time that the continuous CRID of scattering biotissue over a continuous spectral region is measured, and we hereby have proven that CCRIDM-IR is a good method for continuous CRID research of biotissue.

Section: Methodssupporting

confidence: 76%

Section: Error Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Determination of continuous complex refractive index dispersion of biotissue based on internal reflection

Wang

et al. 2016

J. Biomed. Opt

Self Cite

“…1 , which is similar to Ref. 21 , four arms labeled L1, L2, L3, and L4 are connected by high precision bearings with intersection points J1, J2, J3, and J4. A slider fixed on J1 can move along the lead screw, driven by a stepper motor.…”

Section: Methodssupporting

confidence: 71%

Measurement of the refractive index of whole blood and its components for a continuous spectral region

Liu

et al. 2019

J. Biomed. Opt.

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. The refractive index of blood is a key biophysical parameter, which can reflect the physiological state. We measured the refractive index of whole blood and other components, such as serum, plasma, and hemoglobin, based on internal reflection by using a homemade apparatus in the spectral range of 400 to 750 nm. In addition to the hemoglobin solution, which has a Soret band about 420 nm and two Q-bands between 500 and 600 nm, the measurements of other samples are the normal dispersion curve. The results are approximated by the Cauchy equation and Sellmeier equation, and the correlation coefficients are more than 0.997.

“…Recently, we proposed a lab-made apparatus that can measure the light internal reflectance over a wide spectral range. 1,[12][13][14] In this study, the apparatus was applied to measure the CRID of the strong absorbing materials (magenta, yellow, and cyan inks) to test its feasibility.…”

Section: Introductionmentioning

confidence: 99%

Complex Refractive Index Dispersion of Strong Absorbing Material Determined Using Internal Reflectance Spectra Measurement

Wang

et al. 2018

Appl Spectrosc

Self Cite

Complex refractive index dispersion (CRID) of offset inks is an important spectral property that affects the quality of printing. Due to the strong absorption of offset inks, great difficulty exists when measuring their CRID. In this study, a recently proposed apparatus that can detect the internal reflectance spectra was used to measure the CRID of three strong absorbing offset inks (magenta, yellow, and cyan). Both anomalous dispersion curve and extinction coefficient curve were well determined over the spectral range of 400-750 nm. This study experimentally proves that the apparatus and related method are feasible for the CRID measurement of strong absorbing materials and could serve as a powerful measuring tool for optical parameters.