PhotonicVASEfit: VASE fitting tool

By Ludmila Prokopeva1, You-Chia Chang, Alexander V. Kildishev (editor)2

1. Novosibirsk State University 2. Purdue University

Retrieves optical constants of a material by fitting it to VASE (Variable Angle Spectroscopic Ellipsometry) data

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Version 1.3.2 - published on 18 Jun 2015

doi:10.4231/D3JH3D373 cite this

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    PhotonicVASEfit Fitting results: RPA, spline and CP



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PhotonicVASEfit is a tool to fit optical constants of materials to the data obtained with Variable Angle Spectroscopic Ellipsometry (VASE). The tool is initially designed to retrieve the surface conductivity of a single layer graphene sheet deposited on a substrate. Built-in support includes a graphene specific integral model - RPA (Random Phase Approximation). Among general built-in models are Splines and Critical Points (CP) model (relaxed Lorentz oscillators). Furthermore, any custom user-defined material model (defined as a Matlab function)  could be used. Current version supports a structure of 2D material layer on a substrate. Extensions to a more general geometry and support for more materials are expected in next versions.

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Team Credits:

Dr. Ludmila J. ProkopevaSolver Development and Optimization (incl. Spline, RPA, CP and custom function fitting; material database organization), GUI design and development (incl. interactive database access and data selection), nanoHUB Staging and Tutorials

You-Chia Chang - Experimental SupportSolver Development (initial Spline fitting solver)

Prof. Alexander V. Kildishev - Development Supervision 

Prof. Theodore B. Norris - Overall Management


Prof. Alexandra Boltasseva – for useful discussions

Dr. Naresh K. Emani - for experimental support and many instrumental discussions

Di Wang - for experimental support

Sponsored by

  • NSF Materials Research Science and Engineering Center (MRSEC) program DMR1120923
  • AFOSR Multidisciplinary University Research Initiative (MURI) grant no. FA9550-14-1-0389


  1. Y.-C. Chang, C.-H. Liu, C.-H. Liu, Z. Zhong, and T. B. Norris, “Extracting the complex optical conductivity of mono- and bilayer Graphene by ellipsometry,” Appl. Phys. Lett. 104(26), 261909 (2014).
  2. L. J. Prokopeva, and A. V. Kildishev “Time Domain Modeling of Tunable Graphene-Based Pulse-Shaping Device (invited),” in Computational Methods in Nanoelectromagnetics in Applied Computational Electromagnetics ACES 2014, March 23 - 27, 2014 Jacksonville, Florida (CD-ROM).
  3. L. J. Prokopeva, N. K. Emani, A. Boltasseva, and A. Kildishev, "Tunable Pulse-Shaping with Gated Graphene Nanoribbons," in CLEO: 2014, OSA Technical Digest (online) (Optical Society of America, 2014), paper FM4C.2.
  4. L. J. Prokopeva, N. Emani, A. Boltasseva, and A. V. Kildishev, "Experimentally Fitted Time Domain Modeling of Graphene-based devices," MRS Spring meeting, San Francisco, CA, USA, April 6-10, 2015.
  5. D. Wang, N. K. Emani, T. Chung, L. Prokopeva, A. V. Kildishev, V. M. Shalaev, Y. P. Chen, and A. Boltasseva, "Plasmon Resonance in Single- and Double-layer CVD Graphene Nanoribbons," in CLEO: 2015, OSA Technical Digest (online) (Optical Society of America, 2015), paper FTu1E.3.
  6. Y. M. Altman. Undocumented secrets of MATLAB-Java programming. CRC Press, 2011.

Cite this work

Researchers should cite this work as follows:

  • Ludmila Prokopeva, You-Chia Chang, Alexander V. Kildishev (2015), "PhotonicVASEfit: VASE fitting tool," (DOI: 10.4231/D3JH3D373).

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