News Article
Sofradir boosts performance of HOT MCT infrared detector
The firm's newest L-HOT MWIR tool, based on mercury cadmium telluride technology, offers thermal equipment makers power efficiency with no trade-off in detection range
Sofradir, a developer and manufacturer of infrared detectors for military, space and industrial applications, is touting a prototype High Operating Temperature L-HOT MWIR integrated detector cooler assembly (IDCA) that offers a significantly improved detection range over earlier models.
The French headquartered firm will showcase the product at Eurosatory, the biennial international Land Defence and Security exhibition at stand F360-HALL 6, taking place between June 11th and 15th near Paris.
Sofradir says the L-HOT MWIR demonstrator meets system integrators' requirements to reduce SWaP (Size, Weight and Power) in military equipment.
“Producing infrared detectors that are compact, lighter and save energy is driving much of our developments at Sofradir,” says David Billon-Lanfrey, VP R&D at Sofradir. “L-HOT MWIR ensures that customers get a high operating temperature IR detector with all the gains and no trade-off in image quality and NETD in order to keep the highest detection range.”
NETD (Noise-Equivalent Temperature Difference), the signal over noise ratio of the IR detector is an important attribute for evaluating image quality and detection range (the ability to see smaller objects at greater distances in all weather conditions).
An IR chip with high standard NETD performance is more apt at detecting slight differences in temperature between objects. This provides more detail and more accurate images, which is desirable for users looking for SWaP reductions in hand-held thermal imagers, small gimbals for small Unmanned Aerial Vehicles as well as long endurance systems, such as border surveillance or 24 hour surveillance.
Yet, with high operating temperature IR detectors and increased power efficiency comes dark current (useless information like noise) that can interfere with NETD. By using a p-on-n MCT photodiode technology, Sofradir believes it has overcome the dark current problem, while keeping the nominal five-micron cut-off wavelength.
“To achieve a cut-off wavelength at five microns that enables L-HOT MWIR to offer low power consumption in a full performance IR detector with no trade-off in NETD, Sofradir switched to a p-on-n photodiode technology,“ points out David Billon-Lanfrey, VP R&D at Sofradir.
“With a cut-off wavelength at four microns obtained with other technologies, there are fewer input photons on the IR detector and the NETD is degraded. Our L-HOT MWIR prototype has a cut-off wavelength of five microns at 150K and that is a significant achievement.”
The TV format 15 micron pitch L-HOT MWIR integrated detector cooler assembly prototype operates at 150K (-123°C). The firm says this is 60K higher than standard MCT IR detectors (90K, -183°C) in the three to five-micron waveband and consumes less than 2 W.
Today, it achieves the same NETD (better than 20mK) as Sofradir’s standard full performance mid-waveband IR detectors.
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