new use for those computer goggles

[T3D Peter Abrahams <telscope@xxxxxxxxxx>]

I found this on SPIE's web site.  It sounds like something that could have
a lot of applications, viewing low contrast objects:
4 November 1997 
Sandia National Laboratories: evidence-detection system to identify organic
material. The system, with a flashing lamp and a pair of modified
three-dimensional goggles ..........
The heterodyning principle ... is being used ...to apply fluorescence to
DNA sequencing, and to detect cancerous lesions in tissue samples. 
Since organic substances give off weak fluorescent emissions,
which are normally not visible to the naked eye due to the
interference from brighter sources of light, the heterodyning
technique takes advantage of contrast between two signals at
slightly different frequencies. The system's lamp is modulated
to a specific frequency flashing too fast for the human eye to
detect. The glasses shutter open and closed at a slightly
different frequency, which has the effect of turning the user's
eyes on and off at a rate too fast to be detected by the human
eye and making the lenses appear transparent. About twice a
second there is an overlap at which the glasses shutter open
at the exact moment the lamp is turned on. For a split second
the background light whose wavelengths are different than that
of the lamp is drowned out. When the background light is
masked, the fluorescing materials appear to flash brightly at a
rate distinctly noticeable to the human eye. 

_______________________________________
Peter Abrahams   telscope@xxxxxxxxxx
the history of the telescope, the microscope,
    and the prism binocular


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