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FAIR optical constants: A new software tool


OCDB logo and Software Interface

The optical constants fully describe how a material transmits, reflects, absorbs, refracts or scatters light. Their precise knowledge is therefore of central importance for optical technology. As part of the European joint projects "Advanced Traceable Metrology for Optical Constants" (ATMOC) and "14 Angstrom CMOS IC technology" (14ACMOS), PTB has started to build up a database of optical constants of thin films in the extreme ultraviolet spectral range: the Optical Constants Database (OCDB) (https://www.ocdb.ptb.de/). This database focuses on materials, in particular metals, composites and alloys, which are important for applications in (EUV) lithography.

To utilise the database, software has now been developed in the Python programming language that enables easy access to both the data and the associated metadata, including references for each data set. The Python package is published under a free licence, can be installed from common package sources, is comprehensively documented and follows proven software development procedures to ensure high code quality, long-term maintainability and further development. The aim of the OCDB database is to make data, measurement uncertainties and relevant metadata traceable, citable and easily accessible in accordance with the FAIR principles (findable, accessible, interoperable, reusable).

The data in the OCDB are constantly updated and continuously expanded regarding the wavelength range and number of materials. Similarly, the associated Python package will be further developed. Provisioning the optical constants by PTB, both as database and accompanying Python package for easy access to this data, supports the development of optical technologies at short wavelengths, EUV lithography and new optical metrology concepts for nanostructures and thus the industry in Europe.


Python-Paket: https://ocdb-data.rtfd.io/

OCDB: https://www.ocdb.ptb.de/


T. Biskup, 7.1, e-mail: till.biskup(at)ptb.de

V. Soltwisch, 7.14, e-mail: victor.soltwisch(at)ptb.de

N. Hegemann, 8.43, e-mail:nando.hegemann(at)ptb.de