OPTICAL DESIGN OF THE SUBMILLIMETER HIGH ANGULAR RESOLUTION CAMERA (SHARC)

The optical and mechanical design and performance of the Submillimeter High Angular Resolution Camera (SHARC) is described. The camera curre ntly operates with a monolithic 24-pixel linear bolometer array in the 350 and 450 mu m atmospheric windows at the Caltech Submillimeter Obs ervatory (CSO). The design extends the techniques of geometric optics employed in optical and near-infrared cameras to submillimeter wavelen gths. Using an off-axis ellipsoidal mirror and cold stops, excellent i maging (Strehl ratio >0.95) is achieved across a 2' by 2' focal plane field even with secondary throws of up to 4'. The camera's symmetric m echanical assembly provides fixed, machined alignment of the optical e lements. We demonstrate the imaging capabilities of the system with 35 0 mu m observations of a point source at the telescope. The optical de sign can easily accommodate future planned upgrades to two-dimensional bolometer arrays.