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Only a very few examples of near-infrared wavefront sensors can be found in the litterature. However, none of these sensors provide routine observation yet. Our sensor is the only one to be operated routinely on a large AO system. Entirely cryogenized, this sensor is built around a so-called HAWAII array from Rockwell (HgCdTe, 1024×1024). It is working in the huge spectral band ranging from 0.8 to 2.55 microns, and may use -when required- all the flux from this very whole band. It allows to switch between several optical configurations in order to match all atmospheric and observing conditions, while its original mechanical design allows to keep, even at cryogenic temperatures, a mechanical stability lower than 4 microns in any position. It also has some particular read-out schemes, allowing to obtain frame rates as high as 1200 Hz while keeping a read-out noise performance of 10 electrons rms/pixel. The analysis of the design parameters (pixel size, field of view) is exposed in this article. Some results, obtained during the comissioning runs at ESO, will also be presented.

We present preliminary results of injection tests in single mode fibers, conducted in August 2002 at Canada-France-Hawaii Telescope. Single mode fibers for J, H and K band where placed at the focus of the adaptive optics PUEO. The goal of this experiment was to prepare the next step of the OHANA project: an interferometric fiber link between two telescopes on top of Mauna Kea.

When combined with Adaptive Optics, integral field spectroscopy, i.e. observation of a sky field simultaneously in a number of spectral passbands, is the most efficient way to perform spectro-imaging at high angular resolution. GriF will provide the CFHT community with such a capability in the near infrared K-band. This extension will be completed by means of two simple optical devices to be installed in the KIR cryostat (the infrared camera of PUEO): a cooled grism in the filter-wheel and a cold aperture on an entrance focal plane wheel. They will be completed by a room-temperature Fabry- Perot (FP) interferometer in front of KIR. The FP selects narrow bandpass images while the grism spatially separates them, giving a 3-D spectroscopic capacity within a compact and light design. At each exposure, several (up to 9) monochromatic images of a rectangular field of about 36 arcseconds X 4 arc-seconds will be simultaneously acquired, allowing a precise subtraction of continuum and background. The cooled grism will guarantee a low background environment, thus a good sensitivity at K. The medium spectral resolution (about 2600) will fit to a number of programs and will represent a considerable improvement on imaging with narrow- band filters. Thus, combining high angular resolution with the spectroscopic diagnosis, GriF will allow the study of a large class of compact objects or structures, especially in the extragalactic domain where its sensitivity should be unique.