ULTRASPEC optics page

8 September 2014

This page brings together all of the documents and data files related to the ULTRASPEC optical design. The optics were designed by Tully Peacocke, manufactured by ICOS, and are described in the ULTRASPEC+TNT MNRAS paper. The list below is in reverse chronological order, so the higher up the list the more recent the file.

  1. Zemax file of the as-built ULTRASPEC optics.
  2. Adhesives AGF file for ULTRASPEC.
  3. Spreadsheet comparing the as-built lenses with the original design.
  4. Zemax file of the as-built TNT from Christophe Buisset (NARIT), with an accompanying email and powerpoint presentation.
  5. Zip archive containing the original ULTRASPEC optical design sent for manufacture to ICOS, in the form of a word document describing the design and JPEG drawings of each lens, plus the associated ULTRASPEC Zemax file and (assumed) TNT Zemax file.

Throughput curves for each component of the ULTRASPEC system are listed below, along with the total throughput of the instrument as a function of wavelength, courtesy of Liam Hardy.

  1. Atmospheric transmission at airmass 1 for the TNT, where we've added 10% to the Observatorio del Roque de los Muchachos (also at altitude ~2400m) values.
  2. Individual lens transmissions for each of the lenses in the ULTRASPEC lens barrels, including both reflection losses at each surface and absorption losses due to the as-built thickness of each lens. Note that this does not include the losses due to the cement in the doublets - see below.
  3. Total lens transmission for all of the lenses, not including the filter and the adhesives used in the doublets, i.e. all of the columns in the item above multiplied together.
  4. Liam's lens spreadsheet, which contains the AR coating throughput for each lens and the absorption losses due to the as-built thickness of each lens in separate columns.
  5. Transmission of the cement used in the two ULTRASPEC doublets, NOA88 (between lens 4 and 5) and RTV615 (between lens 6 and 7).
  6. SDSS filter transmission, as measured by Asahi for our as-built filters.
  7. CCD QE of the ULTRASPEC EMCCD, with e2v's standard mid-band anti-reflection coating.
  8. Total throughput of ULTRASPEC, including the atmosphere (airmass 1 at the TNT), telescope mirrors (uncoated Aluminium, x4), lenses, lens AR coatings, adhesives and CCD QE, for each filter (u', g', r', i', and z').
  9. Liam's throughput spreadsheet, in ods and xlsx formats, which uses all of the above data to calculate the total throughput of ULTRASPEC.