[Laser] 10 micron IR generation and detection

[stuart.wisher at talktalk.net]

Tim,


Interested in your discussion regarding long wavelength IR, I have here in my junkbox a pyroelectric detector, type E600STO which detects IR from 5um to 14um.
It is similar to types listed on this datasheet:



http://www.farnell.com/datasheets/6575.pdf



These are ceramic ferroelectric sensing elements with silicon filters that generally cut off shorter than 5um waves (although that varies according to type).
They are generally found in PIR motion detectors that use multiple fresnel lenses to detect human or animal body heat, creating a signal as the heat source moves from one lens to another generating a step change in the IR detected. They should detect low frequency modulated IR, but no guarantees, I have not tried it.  It would be nice to see if the radiation from the photo diode mentioned earlier could be detected by one of these. 


A source could be a simple black body radiator but to produce a peak at 10um would require a very low temperature, as according to standard Physics theory, the hotter the body, the shorter the wavelength which goes along with more power output . Better instead to use a hotter source that would as a by-product, produce more IR at the required wavelength. I think the filament light bulb could be as good as anything, well under run and perhaps with some sort of filter. data rates would be low though.


Currently, I am at the other end of the spectrum having made a QSO using ultra-violet radiation......


Regards,


Stuart, G8CYW