CFHT, Instruments, Detectors, IR, KIR


A 1k x 1k IR camera for AOB/PUEO


KIR is a high resolution 1024 x 1024 near-infrared camera based on the Rockwell Science Center HAWAII (HgCdTe Astronomical Wide Area Infrared Imaging) focal plane array. This array is sensitive to radiation from 0.7 to 2.5 microns. KIR has been designed to be used at the F/20 output focus of PUEO, the CFHT Adaptive Optics Bonnette (AOB). It consists in an LN2 cryostat which harbors the detector, the fixed 0.67:1.0 transfer optics, an F/20 cold stop and a filter wheel. The standard I, J, H, K and K' broad-band filters are available, as well as several narrow-band filters. A preamplifier and a shutter are mounted externally to the dewar. The system is driven by an SDSU/Leach CCD controller which is the controller commonly used at CFHT for all visible and infrared detectors. The system provides the observers with a user interface , called DetI, incorporated into the CFHT/Pegasus observing environment, through which they will configure the camera, control the data acquisition, monitor the data storage and do some pre-processing.

The Dewar has been constructed by the Universite de Montreal. The acquisition system and software were under the responsability of CFHT. The final integration of the science grade detector has been carried out at CFHT. The first light has been obtained during the first technical run in September 1997 and the final acceptance as well as the first astronomical observations were carried out in December 1997 and January 1998.

The following picture from KIR on PUEO was taken during the September 1997 technical run.

The following drawing gives the design of the cryostat as of August 1996 Dewar design


Detector format 1024x1024
Detector material HgCdTe
Readout Direct readout (4 channels)
Spectral range 1-2.5µm
Pixel pitch 18.5µm
Filling factor 100 %
Operating temperature 77 K
Strehl ratio at 2.2 microns > 0.9
Readout noise ~ 20 e-/pixel
Dark current 0.15 e-/sec
Full well capacity 100.000 e-
Mean quantum  efficiency  (detector only) 65 %
Conversion factor 3.6 e-/ADU
Minimum integration time 0.1 sec
Maximum integration time 1 hour
Readout time (full frame) 9 seconds
Plate scale 0.0348 arcsec/pixel
Total field of view 36"x36"
Orientation on the sky North up, East left within 2 degrees


CFHT selected Rockwell HAWAII array number #9-77R-2 as science grade array for KIR on 7 Feb 1997. This array has a mean QE of 65.33% for 99.57% of the array. The response nonuniformity is better than 9.49%. The mean dark current is 0.2 e-/sec.

Different acquisition modes are available: one image per file, a cube of a given number of frames with the same integration time per file, the resulting image of a given number of coadds (power of 2).

For the time being, the readout noise is about 20e- but a multiple sampling readout mode (MSR) may be implemented in the near future, and would allow to reach a typical readout noise of less than 5e- for integration times longer than 1minute.

Here is a dark map and here is a flat field as received from Rockwell.

More information about the Rockwell HAWAII arrays in general can be found at at Rockwell's HAWAII array page

Other usefull references:


The KIR camera is equipped with one filter wheel designed to hold 16 1/2 inch filters. The following broad-band and narrow-band filters are available for general use with KIR in semester 98II:

Broad-band filters:
CWL (microns)
FWHM (microns)
T (%)

Narrow-band filters:
Filter CWL (microns) FWHM (microns) T (%)
HeI_I 1.083 0.010 60
Pa Gamma 1.094 0.010 60
J continuum 1.207 0.015 65
[OII] 1.237 0.012 60
Pa Beta 1.282 0.012 60
H continuum 1.570 0.020 65
[FeII] 1.644 0.016 60
[FeII] continuum  1.690 0.018 65
H2 (1-0) 2.122 0.021 60
Br Gamma 2.166 0.022 60
H2 (2-1) 2.248 0.022 60
K continuum 2.260 0.060 65
CO (2-0) 2.296 0.023 60

Note: Visitor filters can also be installed on the KIR filter wheel by the CFHT technical staff, provided that they are made available in Waimea at least 3 weeks prior to the beginning of the corresponding observing run, and subject to the limitations of the 16 position filter wheel. Please note that the diameter and thickness of the visitor filters have to respectively be 12.7 mm (1/2 inch) and 5 mm (0.2 inch).



KIR User's Manual:

AOBIR Cookbook:

AOBIR Filters:

For more information, contact:
Dr. Olivier Lai ( - support astronomer.
Dr. Thierry Forveille ( - support astronomer

Created 21 February 97.
Page created by Jean-Luc Beuzit and Marie-Claire Hainaut, with some minor updates by Thierry Forveille.
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