As-built optical models for the LDT
Please contact Tom Bida to request the Zemax models.
A. For folded instrument cube ports, showing the instrument cube and optical geometry:
- The unvignetted FOV of a standard fold mirror is approximately 2.4 arcmin circular diameter, or 1.7 arcmin square.
- The unvignetted FOV of the dichroic fold mirror blank is approximately 4 arcmin circular diameter, or 3 arcmin square.
- The back focus from the instrument mounting flanges for folded cube ports is 180mm.
- The RC plate scale is 8 arcsec/mm.
B. For the RC corrector, with LMI including the dual filter wheel, and surface points for the cube structure and components.
The 2-element corrector has the following characteristics:
- The 2 lenses are fabricated of fused silica, with transmission of 98.5% from 300-1100nm.
- The corrected, unvignetted FOV is 0.5 deg diameter, with 0.03% differential distortion over this FOV.
- The AR coatings provide average reflectance of 0.84% from 300-1100nm, with < 0.025% additive ghost-reflection sky background.
- The modeled spot size is 4.2-6.4 microns RMS (< 0.082 arcsec FWHM) over the LMI FOV (0.205 deg square), for B through I-bands.
The LMI CCD is a deep-depletion e2v CCD-231-C6, 6K x 6K 15 micron pixels, coated with a 4-layer Astro AR coating. The plate scale is 0.12 arcsec/pixel.
- DCT_RCC_LMI.ZMX