Determination of the optical constants of thin films by means of transmission spectra and curve fitting

Hongzhi Jia; Huancai Lu

doi:10.1117/12.865723

16 October 2010 Determination of the optical constants of thin films by means of transmission spectra and curve fitting

Hongzhi Jia, Huancai Lu

Proceedings Volume 7656, 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment; 76565G (2010) https://doi.org/10.1117/12.865723
Event: 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies, 2010, Dalian, China

Abstract

A method to calculate the optical constants (refractive index n, film thickness d and extinction coefficient k) of double-coated thin film by use of transmission spectrum is described in this paper. For double-coated glass films, the relationship between T, λ, n, k and d is analyzed theoretically. Then the method to determine these optical parameters by curve fitting is introduced. Several samples with different Sn concentrations have been prepared. According to the method mentioned above, we calculate the coefficients of Sn-doped SiO₂ films produced by Sol-gel method. Two kinds of expressions for the refractive index n are introduced. One is Cauthy model. The other is defined as Polynomial model. Also the expressions for k are given similarly. At last, the experimental curves are fitted according to the transmittance formula. Results show that the refractive index becomes larger with the increase of Sn in the compound. Also, it turns out that the refractive index decreases when the wavelength increases. This method combines the extreme point method with the whole transmission spectra fitting method. This can improve the fitting accuracy.

Citation Download Citation

Hongzhi Jia and Huancai Lu "Determination of the optical constants of thin films by means of transmission spectra and curve fitting", Proc. SPIE 7656, 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, 76565G (16 October 2010); https://doi.org/10.1117/12.865723

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
6 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Refractive index

Thin films

Transmittance

Tin

Absorption

Glasses

Silica

Show All Keywords

Keywords/Phrases

Search In:

Publication Years