[Laser] Strange effect

[Tim Toast]

Hi Yves
I would have to agree with the other responces you got and say the photodiode is emitting 1 or 2 microns and the pyrodetector is either seeing the 2 micron weakly (at the upper edge of its bandwidth) or is just responding to the heat generated near 10 microns. The germanium detector is seeing the radiation directly and so has the best responce. Makes sense :-) ...it is still strange to see a detector emit light at such a far removed wavelength, when LED's detect at almost the same wavelength - differences in construction i imagine.

-toast


Message: 1
Date: Mon, 12 Mar 2012 15:02:27 -0400 (EDT)
From: f1avyopto at aol.com
Subject: [Laser] Strange effect
To: laser at mailman.qth.net
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Hi all
I need some help to evaluate a strange effect
I try today to bias direct way some PIN silicon phodiodes with a rather high current.
Some large area epoxy case photodiodes (1 cm?) was biased to 20 mA without apparent damage.
In dark condition I cannot see any light but a K3PGP RX with a silicon photodiode receives a signal to 20 cm...
A germanium phototransistor gives a strongest response...
I got also a solid signal with a pyroelectric detector from a motion detector.
What could be the bandwidth and the spectrum of this produced light ?
Thank you for the help.
73
Yves F1AVY
http://f1avyopto.wifeo.com/