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From: rob@portia.Stanford.EDU (Robert Barrett)
Newsgroups: sci.electronics
Subject: LED inquiry
Message-ID: <10400@portia.Stanford.EDU>
Date: 21 Mar 90 18:23:39 GMT
Sender: Robert Barrett <rob@portia.stanford.edu>
Reply-To: rob@portia.Stanford.EDU (Robert Barrett)
Distribution: usa
Organization: Stanford University
Lines: 17


I am in need of a special-purpose LED and was wondering if the net might
be able to point me in the right direction:

I want to use an LED as the light source for a positioning system.  The
requirement is to produce a spot (approximately 1mm diameter), about
1/2" away from the LED with a power of at least 1mW.  I'll be using a
silicon detector so any wavelength from near IR to red is fine.
Unfortunately, most LED's are designed to have wide divergence angles
instead of being focused. I would like to avoid adding my own lenses as
space is really tight in my application.  Any ideas?   I would also like
to avoid laser diodes as they are somewhat less reliable, more costly,
and have more of a problem with amplitude noise.

Thanks for any help,
Rob Barrett
rob@portia.stanford.edu