Prototype-testbed for infrared optics and coronagraph (PINOCO)

We present the Prototype-testbed for Infrared Optics and Coronagraphs (PINOCO) which is a large, multi-purpose cryogenic chamber. At present, the priority for PINOCO is to evaluate binary pupil mask coronagraphs in the mid-infrared wavelength region, which are planned to be adopted for the SPICA coronagraph instrument. In addition, various other experiments are possible using PINOCO: testing diverse high dynamic-range techniques, mirrors, active optics, infrared detectors, filters and spectral dispersion devices, the mechanics of the instruments, measurement of material properties, and so on. PINOCO provides a work space of 1m × 1m × 0.3m, of which inside is cooled to <5K. Flexible access to the work surface is possible by removing detachable plates at the four sides and on the top of the chamber. At the interface to the exterior, PINOCO is currently equipped with an optical window, electric connectors, and an interferometer stage. PINOCO is cooled by two GM-cycle cryo-coolers, so no cryogen is needed. A cooling test of PINOCO was successfully completed.