Posted by John Trauger (JPL) on June 24, 1999 at 16:48:32:
A summary of the WFPC2 spare grisms for the WFC3 strawman option list. A grism-CCD separation of 450 mm was assumed for the dispersion estimate. Red grism G800 8.22 gvs/mm Blocked to cover 5700 Angstroms and longward in first order Rays are undeviated at the blaze wavelength of 8850 Angstroms Dispersion ~ 40 Angstroms / CCD pixel Blue grism G450 16.2 gvs/mm Blocked to cover 3600-6200 Angstroms in first order Rays are undeviated at the blaze wavelength of 5000 Angstroms Dispersion ~ 20 Angstroms / CCD pixel UV grism G200 25 gvs/mm, ruled on a CaF2 substrate Blocked shortward of 1650 Angstroms by SiO2 optics Prism is cross dispersed to separate diffraction orders Dispersion ~ 13 Angstroms / CCD pixel in first order