| 摘要 |
PURPOSE: To measure the refractive index of a substance having unflat surface, e.g. skin, as it is by determining the reflectance of a sample based on the reflective intensity of the micro facet of the sample at a specified azimuth and the shape distribution function. CONSTITUTION: Light is projected to a sample at a different projection angleαand the reflected light for each projection angleαis received at a plurality of different light receiving anglesβ. The angleθ=(α+β) 12 is then determined along with the reflective intensity R (θ,ϕ) of a microfacet at an azimuthϕ. Furthermore, shape distribution function G (ϕ) of the microfacet is determined and then a reflectance F (θ) is determined from the intensity R (θ,ϕ) and the function G (ϕ) according to Fresnel's formula. The reflectance F (θ) thus determined is fitted to Fresnel's formula thus determining the reflectance (n) of the sample. With such arrangement, the refractive index can be measured, as it is, even for an unflat sample, e.g. skin.
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