| Popis: |
FLITECAM is a facility class instrument on SOFIA, operating form 1-5 microns. A 1024 by 1024 InSb ALADDIN II array will be used in a fully refractive optics system that provides three optical modes; imaging at a plate scale of 0.47 inch by 0.47 inch per pixel and afield of view of 8 feet, grism spectroscopy with moderate resolutions of about R equals 1000- 20000 depending on the slit width used, and a pupil viewing mode. The plate scale is achieved by using an f/4.8 back-end camera behind an f/4.9 collimator. The 8 foot field of view of SOFIAs f/19.6 telescope translates to a focal plane aperture of 114mm. The collimator optics are therefore quite large with a diameter of almost 170mm. Between the pupil image produced by the collimator and the f/4.8 camera, a ste of three lense will be inserted to achieve a pupil viewing mode. The optical train is entirely refractive, with triplets or split triplets using combinations of LiF, BaF 2 , ZnS, and ZnSe. The design of an optics system with this wide a wavelength range of more than two octaves and the large field of view present a challenging project. We demonstrate that our optical design meets the performance requirements with certain allowed lens-fabrication and misalignments built in. |
