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Sorry if this is a dumb question: Reading your link, it sounds like the HgCdTe-based FPAs are primarily an electrochemical thing, akin to the microchannel plat

Sorry if this is a dumb question: Reading your link, it sounds like the HgCdTe-based FPAs are primarily an electrochemical thing, akin to the microchannel plate approach of traditional analog image intensification. My impression of more modern IR-spectrum imaging (Teledyne/BAE/L3 stuff) was that it is basically a bolometer sensor behind vanadium/germanium-doped glass, then somehow hooked up to a cmos sensor. So, modern sensors are still partially based in an electrochemical process, just a different one that's more amenable to improvements in manufacturing process or something? I'm thinking of some of the new stuff that can deliver 1920x1080 60hz output - that'd definitely help with targeting.

jpmattia 5y ago
> it sounds like the HgCdTe-based FPAs are primarily an electrochemical thing HgCdTe is a semiconductor like Si or GaAs, but it has a much smaller bandgap. > My impression of more modern IR-spectrum imaging (Teledyne/BAE/L3 stuff) was that it is basically a bolometer sensor Bolometers rely on heating. HgCdTe (& CMOS imagers) rely on photon generation of electron-hole pairs, which is an altogether different mechanism. > behind vanadium/germanium-doped glass The most common reason for putting Ge in front of an IR imager is to filter out more energetic photons (ie, visible light), since those will also be detected by most IR imagers. > I'm thinking of some of the new stuff that can deliver 1920x1080 60hz output - that'd definitely help with targeting. Yes. State of the art is UHD, eg https://www.teledyneimaging.com/en/aerospace-and-defense/products/sensors-overview/infrared-hgcdte-mct/ https://www.teledyneimaging.com/en/aerospace-and-defense/pro... The issue will be the product cycle, which for the military is extremely long.
- livueta 5y ago
  I appreciate the reply, this cleared up some misconceptions.

jpmattia 5y ago

> it sounds like the HgCdTe-based FPAs are primarily an electrochemical thing HgCdTe is a semiconductor like Si or GaAs, but it has a much smaller bandgap. > My impression of more modern IR-spectrum imaging (Teledyne/BAE/L3 stuff) was that it is basically a bolometer sensor Bolometers rely on heating. HgCdTe (& CMOS imagers) rely on photon generation of electron-hole pairs, which is an altogether different mechanism. > behind vanadium/germanium-doped glass The most common reason for putting Ge in front of an IR imager is to filter out more energetic photons (ie, visible light), since those will also be detected by most IR imagers. > I'm thinking of some of the new stuff that can deliver 1920x1080 60hz output - that'd definitely help with targeting. Yes. State of the art is UHD, eg https://www.teledyneimaging.com/en/aerospace-and-defense/products/sensors-overview/infrared-hgcdte-mct/ https://www.teledyneimaging.com/en/aerospace-and-defense/pro... The issue will be the product cycle, which for the military is extremely long.

livueta 5y ago
I appreciate the reply, this cleared up some misconceptions.