Performance of anisotropically-etched gratings in the extreme and far ultraviolet bandpasses

Nicholas Kruczek, Fabien Grise, Drew M. Miles, Chad Eichfeld, Brian Fleming, Randall McEntaffer, Kevin France, Stephan McCandliss

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Modern grating manufacturing techniques suffer from inherent issues that limit their peak efficiencies. We describe work in collaboration with the Nanofabrication Lab at Penn State University to design and characterize etched silicon gratings optimized for the extreme (EUV; 10-90 nm) and far ultraviolet (FUV; 90-180 nm) bandpasses. We develop this technology by fabricating a variety of gratings that operate over these bandpasses. We present analyses for two different grating designs in this work. The first is an FUV echelle that has similar parameters to the grating own on the CHESS sounding rocket. CHESS was an FUV spectrograph that utilized a mechanically ruled echelle grating. We compare the efficiency and in-instrument performance of the gratings, finding a ∼ 50% increase in groove efficiency and an 80% decrease in inter-order scatter for the etched gratings compared to their mechanically ruled counterpart. The FUV echelle improvements can ultimately benefit the faint source sensitivity and high-resolution performance of future UV observatories, such as LUVOIR, by reducing the non-uniform inter-order backgrounds that have historically plagued echelle spectrographs. We additionally provide a description of how this lithographic process can be extended to gratings with holographic solutions by discussing our procedure for generating a map of groove traces from holographic recording parameters. This discussion is provided in the context of the creation of a grating sample that was developed in support of the ESCAPE Small Explorer Phase A study.

Original languageEnglish (US)
Title of host publicationUV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XXII
EditorsOswald H. Siegmund
PublisherSPIE
ISBN (Electronic)9781510644809
DOIs
StatePublished - 2021
EventUV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XXII 2021 - San Diego, United States
Duration: Aug 1 2021Aug 5 2021

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume11821
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceUV, X-Ray, and Gamma-Ray Space Instrumentation for Astronomy XXII 2021
Country/TerritoryUnited States
CitySan Diego
Period8/1/218/5/21

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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