The Large Binocular Telescope Interferometer, a thermal infrared imager and nulling interferometer for the LBT, is
currently being integrated and tested at Steward Observatory. The system consists of a general purpose or universal
beamcombiner (UBC) and three camera ports, one of which is populated currently by the Nulling and Imaging Camera
(NIC). Wavefront sensing is carried out using pyramid-based "W" units developed at Arcetri Observatory. The system
is designed for high spatial resolution, high dynamic range imaging in the thermal infrared. A key project for the
program is to survey nearby stars for debris disks down to levels which may obscure detection of Earth-like planets.
During 2007-2008 the UBC portion of the LBTI was assembled and tested at Steward Observatory. Initial integration of
the system with the LBT is currently in progress as the W units and NIC are being completed in parallel.
LBTI is a thermal imager and a nulling interferometer to be installed on the Large Binocular Telescope (LBT). Here,
we present the distributed component architecture model and its simple yet powerful software structure designed to
complement the LBTI hardware model that comprises pyramid wave front sensors with its control electronic universal
beam combiner, phase sensor, science imager, and all housekeeping duties to run the cryogenics, compressors, vibration
monitors and the interface to the telescope control systems.
Clio is an adaptive-optics camera mounted on the 6.5 meter MMT optimized for diffraction-limited L' and M-band imaging over a ~ 15" field. The instrument was designed from the ground up with a large well-depth, fast readout thermal infrared (~ 3_5μm) 320 by 256 pixel InSb detector, cooled optics, and associated focal plane and pupil masks (with the option for a coronograph) to minimize the thermal background and maximize throughput. When coupled with the MMT's adaptive secondary AO (two warm reflections) system's low thermal background, this instrument is in a unique position to image nearby warm planets, which are the brightest in the L' and M-band atmospheric windows. We present the current status of this recently commissioned instrument that performed exceptionally during first light. Our instrument sensitivities are impressive and are sky background limited: for an hour of integration, we obtain an L'-band 5 σ detection limit of of 17.0 magnitudes ~ 80%) and an M-band limit of 14.5 (Strehl ~ 90%). Our M-band sensitivity is lower due to the increase in thermal sky background. These sensitivities translate to finding relatively young planets five times Jupiter mass (MJup) at 10 pc within a few AU of a star. Presently, a large Clio survey of nearby stellar systems is underway including a search for planets around solar-type stars, M dwarfs, and white dwarfs. Even with a null result, we can place strong constraints on planet distribution models.
Current adaptive optic systems are limited by the read noise and sensitivity of their wavefront cameras. Recent advances in substrate thinning are producing focal plane arrays with high quantum efficiencies and extended spectral response over 0.5 to 1.6 microns. Infra Red Laboratories have developed and tested a new ultra-low noise readout integrated circuit (ROIC) that has a performance of 2 electrons (r.m.s.) per pixel read. We combine these two technologies to produce a new detector capable of dramatically increasing the number of available natural guide stars across the sky (and hence increased sky coverage), even in heavily obscured regions near the Galactic plane.