Refractive index database

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RefractiveIndex.INFO Website and Database

Welcome to the RefractiveIndex.INFO website, your gateway to the database! Database

This comprehensive database of optical constants was initiated and has been maintained by Mikhail Polyanskiy since 2008. It is a compilation of data from publicly available sources such as scientific journal articles and material datasheets published by manufacturers. Numerous researchers have contributed to the database by providing numerical data, reporting bugs, and suggesting improvements.

The database is made freely available under the CC0 1.0 Universal Public Domain Dedication. This means you are free to use, modify, and distribute its content without any restrictions, even for commercial purposes, no permission required.

The database is organized as a library of YAML files. This file format was chosen for its simplicity, clarity, and human readability.

RefractiveIndex.INFO Website

The RefractiveIndex.INFO website serves as a user interface to the database, offering straightforward access to the data and basic calculations such as absorption, Fresnel reflection, and Brewster angle. Mikhail Polyanskiy is the owner and maintainer of the website.

Using the RefractiveIndex.INFO website is not a requirement for accessing the database. Alternative web-based interfaces, Python scripts, and other methods (including direct reading of the YAML files) can be used.


Downloading the Database

You can download the latest release of the database from here:


(See Changelog-nk and Changelog-n2 for the update history)

Visit and Join Us on GitHub

For those who wish to access the most recent, work-in-progress version of the database, or to get involved with the project, visit us on GitHub!

GitHub: - project on GitHub.

GitHub: - Collection of Python scripts related to the database.

Cite or contribute data

How to Cite

Peer-reviewed publication

M. N. Polyanskiy. database of optical constants. Sci. Data 11, 94 (2024)

Web site

M. N. Polyanskiy, "Refractive index database," Accessed on .

Contributing Data

Option A: Any format

E-mail data in any format (TXT, CSV, etc.) or a link to an original publication containing data suitable for inclusion in the database to

Option B: YAML (preferred) database stores data in YAML file format. Submitting pre-formatted data will greatly simplify and accelerate inclusion of data in the database. Use one of the following real-life examples as a template and e-mail the YAML file(s) to

Note: YAML is widely supported across text processors for its syntax highlighting. We recommend Notepad++ for Windows users.

Example 1: Refractive index (n) as a dispersion formula (see List of dispersion formulas)

Example 2: Refractive index (n) as tabulated data

Example 3: Refractive index (n) and extinction coefficient (k) as tabulated data

Example 4: Refractive index (n) as a dispersion formula and extinction coefficient (k) as tabulated data (see List of dispersion formulas)

Example 5: Refractive index (n) and extinction coefficient (k) as two separate sets of tabulated data

Example 6: Nonlinear refractive index (n2) as tabulated data