Paper
21 June 2019 Modelling and tolerance analysis of volume-phase gratings in complex dispersive units
Author Affiliations +
Abstract
In the present study we consider an approach to design and tolerance analysis of a spectrograph with a complex dispersive unit. The design uses a mosaic dispersive unit consisting of two VPH gratings imposed on the same substrate. This solution allows to detect spectra in two intervals – visible (375-625 nm) and near infrared (600-1000 nm) simultaneously. The modeling results show that the spectra resolution reaches 0.78 and 1.25 nm in the visible and NIR channel, respectively. The diffraction efficiency varies between 74.3% and 99.7% for the entire working range. However, the design is sensitive to the manufacturing and assembly errors. Some design parameters have influence on both the image quality and the diffraction efficiency. We developed a set of design tools allowing to include diffraction efficiency data into the tolerance analysis process. The analysis performed with these tools shown that maintenance of the nominal efficiency together with the image quality requires special control over the holographic layer parameters and also tightening of the tolerances on the lenses parameters. The developed analysis approach and tools may be useful in the future for design of spectral instruments with VPH gratings, especially when they are used to build a complex dispersive element.
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Andrey N. Melnikov, Maxim K. Bakshaev, Eduard R. Muslimov, and Ilya A. Guskov "Modelling and tolerance analysis of volume-phase gratings in complex dispersive units", Proc. SPIE 11057, Modeling Aspects in Optical Metrology VII, 110571O (21 June 2019); https://doi.org/10.1117/12.2527425
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Tolerancing

Optical design

Spectrographs

Diffraction gratings

Diffraction

Near infrared

Visible radiation

Back to Top