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What is a dewar?

May 24, 2022

A dewar is a very high vacuum container for the sensor because you have to operate it very cold. It has to be isolated from the atmosphere. Otherwise everything will condense on the sensor. So it’s like an ultra high vacuum in there. They get all the atmosphere out of it so that no air, no particles, no nitrogen, no oxygen, no nothing is in there. 

It’s like the vacuum of space. If we were running this sensor and all of a sudden the vacuum broke, everything would be ruined. Inside this dewar there’s a cold shield. There’s a cold filter. There’s a window through which the radiation comes through. This is either sapphire or silicon. One of them. It’s an infrared compatible window. The light comes in, it hits the sensor. 

The electronics are connected to the sensor through a vacuum feed-through connector. And then we have our interface, which is an FFC connector right here. The electronics processes the signal and a digital signal comes out this connector on an FPC or an FFC and then we run it into electronics that create the rest of the image. 



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