How to calculate refractive index from reflectance values

[Mythili]

Greetings.
how to calculate the refractive index, extinction coefficient, absorption coefficient values from the reflectance data. And also suggest me how to measure the transparency of glass. Is there any relation between transparency and refractive index

Thanks in advance

 

[Simon Bridge]

Welcome to PF;
Concentrating on refractive index:
i.e. http://www.kayelaby.npl.co.uk/general_physics/2_5/2_5_9.html

But it can depend:
http://scitation.aip.org/content/aip/journal/apl/96/23/10.1063/1.3449127

... what level is this to be done at?

 

[Claude Bile]

Not possible using only intensity measurements to my knowledge - you need to know the phase change upon reflection as amplitude to calculate the complex (i.e. refraction + absorption) refractive index.

Extinction and absorption coefficient are basically the same thing, transparency additionally depends on the thickness of the material you are looking at. Absorption coefficient is related to the imaginary component of the refractive index.

Claude.

 

[chris167]

Hi,
do you know how i can calculate the phase shift of measured reflectance data? I find the dispersion relation formula but I can´t solve it.
A step by step description will really help.

thanks
chris

 

[sardar]

for your interest in measuring the properties of glass. To calculate the refractive index from reflectance values, you can use the Fresnel equations, which relate the refractive index to the reflectance coefficient. The equation is n = (1 + R)/(1 - R), where n is the refractive index and R is the reflectance coefficient. The extinction coefficient and absorption coefficient can also be calculated from the reflectance data using the Kramers-Kronig relations. These equations relate the real and imaginary parts of the refractive index to the extinction and absorption coefficients, respectively.

To measure the transparency of glass, you can use a spectrophotometer which measures the amount of light transmitted through the glass at different wavelengths. The transparency of glass is related to its refractive index as the higher the refractive index, the less light will be transmitted through the glass. Therefore, there is an inverse relationship between transparency and refractive index.

It is important to note that the refractive index and transparency of glass can also be affected by factors such as impurities and surface roughness. So it is important to ensure that the glass being measured is clean and free from any defects.

I hope this information helps you in your research. Best of luck!