IR Detector Integrates Cryogenic Cooler
Jul 2008IRnova ABRequest Info
• peak response 8.6 μm
• cools to 70 K in 8 min
• hand-held and mobile device
IRnova AB has released the IRnova384 integral detector Dewar cooler assembly for industrial and military applications. Manufacturers of infrared systems and cameras use the cooled module in long-wave-infrared devices such as hand-held and mobile surveillance systems.
The product makes use of quantum well infrared photodetector technology, in which the absorption of a photon of infrared radiation directly triggers a quantum event. Cryogenic temperatures are necessary to reduce the dark current noise and, by integrating the cooling device, the company has produced a convenient module to assist OEMs in building their cameras. The detector’s output depends on the number of photons absorbed rather than on their energy. The imaging device has a focal plane array with a spatial resolution of 384 × 288, a peak spectral response at 8.6 μm and a bandwidth of 7.5 to 9 μm full width half maximum. Its temperature resolution, measured as the noise equivalent temperature difference, is 25 mK against time and 10 mK spatially. The readout integrated circuit is based on direct injection and is manufactured in a standard silicon CMOS process. The user may select one, two or four outputs, producing maximum frame rates of 80, 150 and 260 Hz, respectively. The integral rotary cooler is a Ricor K548 with 0.75 W of power, and it cools the detector to 70 K in about 8 min.
The module is compact and weighs about 800 g. It operates from a power supply of 18 to 28 VDC and consumes about 25 W during the cool-down stage.