Dear Pranita,

To calculate refractive index you may used Abbe Refractometer or by using the Brewster angle method using He–Ne laser as the source.

Thank you for your valuable comment. Actually, we don't have that expertise so could you kindly suggest me some formula to calculate the same from transmittance or reflectance value?

Hi Pranita,

We measure the refractive index of our prepared glasses using the above two methods.

For your query, you may visit the following link

http://www.kayelaby.npl.co.uk/general_physics/2_5/2_5_9.html

Hope this will help you

Regards

Thank you but my sample is organic.

Dear Pranita,

We have Abbe Refractometer, by which we can measure the refractive index. Actually we are working with powders and glasses. Powder in the form of pallet, or glasses, thin film can be done. What about your organic material, whether it is in powder form or liquid?

I think we can try in our instrument, you can use this facility.

How can I avail yours instrument facility?

My samples are powders.

Can you make pallets or thin film of your powder sample?

Regarding facility, you can send your samples to me.

Yes, pallets we can prepare. Is there any measurement for the pallet.

Is it fine if we prepare like IR pallets?

Pallet of 10 mm dia with 1 mm thickness can be done. or you may send thin film of 10 mm x 20 mm dimension with maximum 1 mm thickness

Could you share your complete mailing address, so that I can post the sample?

How much time it will take to do the experiment?

What kind of material is your powder made of? If the crystallites are anisotropic, it would be required that their diameter is small compared to the wavelength. If you are interested in the UV spectral range, this would mean, that the diameters must be roughly smaller than 40 nm. Otherwise, the light is doubly refracted in each crystallite... see e.g.

Article Optical isotropy in polycrystalline Ba_ {2} TiSi_ {2} O_ {8}...

Yes it is possible. refractive index and dielectric constant both can be calculated by calculating absorption coefficient initially. first of all you have to convert your transmittance data into absorption and then using stand equations you can do the same.