I have absorbance, reflectance% and transmittance% data. How to calculate refractive index from this.
I tried with R = [(n - 1)^2 + K^2 ] / [(n + 1)^2 + K^2] where K is extinction coefficient.
Calculation was done by numerical method. It shows large deviation from reported value.
Kindly suggest how to proceed.
The complex refractive index n∗ is defined as:
n∗ = n − i k,
The refractive index n is determined from reflectance R using the relation:
n =[(1 +√R)/(1 −√R)]
and extinction coefficient k is given by the relation:
k = αλ/4π
Absorption coefficient α is determined from transmittance T by the relationship:
T = exp(−αx), or α = [ln(1/T )]/x
The complex refractive index n∗ is defined as:
n∗ = n − i k,
The refractive index n is determined from reflectance R using the relation:
n =[(1 +√R)/(1 −√R)]
and extinction coefficient k is given by the relation:
k = αλ/4π
Absorption coefficient α is determined from transmittance T by the relationship:
T = exp(−αx), or α = [ln(1/T )]/x
Use swanepoel method if u know the refractive index of the substrate
Ali,
I want to know how to get from the eqn I mentioned above or any other method which uses R and A
Try, (i suppose there is no energy loss from the eam used due to dispersion and scattering in your material)
In general, ref. Index is a function of the wavelength of the incident light, so keep in mind the wavelength at which you are comparing your value with an other .
Hi u can easily find the refractive index as well as thickness of the thin film by using swnepoel method..... By using this method you can find refractive index from transmittance data,,,,,,
HI
Using swanepoel method you will calculate the optical constants.
I am herewith attaching the swanepoel paper for your review.
I hope it will helps you.
Good Luck
hi Naidu Revati mam,
i was very happy to suggest this paper for finding the optical constants.......
as per my knowledge in this paper in equation 22 is not correct it should be (n+1)^3
Dear Naidu
please could you send me your paper about swanapoel method, beacuse i can not download it. my mail
best wishes
Muhammad
Hi friends....
Can you suggest , how to determine the electro chromic properties of thin film from the cyclic voltometer studies...
One of methods to find the refractive index is to measure the reflection coefficient R(w) in the far infrared region after phonon frequency - normally w=200 -300 cm-1. Because R(w)= ((n-1)/n+1))2, you can calculate the refractive index n.
Guys, please
how do i get the optical parameters n, k from the transmittance data for thin films where there are no interference fringes thus swanapoel method may not be used.
You can refer our paper: Journal of Crystal Growth 261 (2004) 77–81. This is a general method. There are few cross references which you will need to consult.
John, please consult our paper: Journal of Crystal Growth 261 (2004) 77–81 as I mentioned above. However, you need both Transmittance and Reflectance data.
Hi all, just a warning here - due to different measurement setups (e.g. if an integrating sphere is used or not; if yes, then where the sample is positioned, etc) can lead to quite a large variation in your A%, R%, T% values. And if these don't add up to 100% then what do you do? I have done this in the past, but now I am lucky enough to have a spectroscopic ellipsometer (300-2000nm) - this is a far mroe powerful and accurate tool for yeilding the values you are looking for. All the best, Bryce
n1=[(1+n2)+((1+n2)2-4n2tm)1/2]/2(tm)1/2
n1=refractive index of sample
n2=refractive index of substrate
tm=transmittance
you can use this formula
Please Mr. Sanjay Kumar do you have any paper about this relation
n1=[(1+n2)+((1+n2)2-4n2tm)1/2]/2(tm)1/2?
Dear Prof. Rama,
Can you provide a published paper that uses the relation you suggested? Thank you very much!
Here some a useful resources. Check with Chapter 7 in:
https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjU18b5qcHfAhXMLlAKHdDwBH8QFjAAegQICRAC&url=https%3A%2F%2Fwww.researchgate.net%2Fprofile%2FJerome_Polesel%2Fpost%2FWhat_is_the_correct_band_gap_determined_by_a_Tauc_plot%2Fattachment%2F59d620fc79197b807797f6da%2FAS%253A293973668188172%25401447100192588%2Fdownload%2FThe%2BPhysics%2Bof%2BThin%2BFilm%2BOptical%2BSpectra_%2BAn%2BIntroduction.pdf&usg=AOvVaw31Ht7GF4cs3jMfQU_EXQzy
and here fom PE:
https://www.perkinelmer.com/lab-solutions/resources/docs/APP_Thin-films.pdf
plus a glimpse in yet another Stenzel book:
http://www.ciando.com/img/books/extract/3642540635_lp.pdf
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Thin Films and Nanotechnology