Spectrophotometric characterization of gradient index coatings

authored by: Stefan Günster, Manfred Dieckmann, Detlev Ristau, David Le Bellac
Abstract: The deposition of gradient index coatings attaches a higher importance for science and also for industrial applications. Especially the progress in chemical vapour deposition technologies opens new opportunities for the production of various types of gradient index coatings. However, the characterization of these types of coatings plays a substantial role in the optimization of coating processes. The spectrophotometric characterization and analysis of gradient index layer coatings is described. SiO_xN_y gradient index coatings were produced in a CVD process, and gradient index TiO₂ layers in an e-beam deposition process with varying ion bombardment. A set of transmission and reflection spectra for different angles of incidence and polarization states was measured. The subsequent data evaluation employs a multilayer model for the gradient index layer to calculate the corresponding spectra. The analysing procedure optimizes the layer system with respect to a minimum deviation between calculated and experimental data. Refractive index data and layer thickness are adapted. Results of gradient index layer systems, three layer coating systems, and homogeneous single layers are presented. The experimental spectra are presented in comparison to the corresponding spectra calculated from the evaluated coating design. The evaluated behaviour of the refractive indices in dependence of the film thickness is discussed in view of the original design for the production process. Also, the influence of measurement errors on the data extraction is demonstrated, as well as the effect of the starting parameters. A good agreement between the simulated and experimental data could be achieved for the gradient index layer system, which demonstrates the versatility of the characterization procedure.
External Organisation(s): Laser Zentrum Hannover e.V. (LZH)
Type: Conference contribution
Pages: 529-538
No. of pages: 10
Publication date: 07.09.1999
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1117/12.360124 (Access: Closed)

BibTeX

@inproceedings{ca7d2b32f80f411fb0f5aeb99feb4fd9,
title = "Spectrophotometric characterization of gradient index coatings",
abstract = "The deposition of gradient index coatings attaches a higher importance for science and also for industrial applications. Especially the progress in chemical vapour deposition technologies opens new opportunities for the production of various types of gradient index coatings. However, the characterization of these types of coatings plays a substantial role in the optimization of coating processes. The spectrophotometric characterization and analysis of gradient index layer coatings is described. SiOxNy gradient index coatings were produced in a CVD process, and gradient index TiO2 layers in an e-beam deposition process with varying ion bombardment. A set of transmission and reflection spectra for different angles of incidence and polarization states was measured. The subsequent data evaluation employs a multilayer model for the gradient index layer to calculate the corresponding spectra. The analysing procedure optimizes the layer system with respect to a minimum deviation between calculated and experimental data. Refractive index data and layer thickness are adapted. Results of gradient index layer systems, three layer coating systems, and homogeneous single layers are presented. The experimental spectra are presented in comparison to the corresponding spectra calculated from the evaluated coating design. The evaluated behaviour of the refractive indices in dependence of the film thickness is discussed in view of the original design for the production process. Also, the influence of measurement errors on the data extraction is demonstrated, as well as the effect of the starting parameters. A good agreement between the simulated and experimental data could be achieved for the gradient index layer system, which demonstrates the versatility of the characterization procedure.",
author = "Stefan G{\"u}nster and Manfred Dieckmann and Detlev Ristau and {Le Bellac}, David",
year = "1999",
month = sep,
day = "7",
doi = "10.1117/12.360124",
language = "English",
isbn = "0-8194-3212-1",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
pages = "529--538",
booktitle = "Advances in optical interference coatings",
address = "United States",
note = "1999 Advances in Optical Interference Coatings ; Conference date: 25-05-1999 Through 27-05-1999",
}