Re: Does this exist? <= .01% @ 365nm, > 90% @ 400nm

Hi,

I found what you need but my emails bounces back. Please send me an email
and I send you the transmission curves.

Regards

Dr K Schmitt
kds315 AT yahoo DOT com


<acannell@xxxxxxx> schrieb im Newsbeitrag
news:1117397582.130883.75340@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> I am looking for an optical filter for a flourescence experiment. The
> excitation wavelength is 365nm, and the emission wavelengths are
> between 400 and 500nm. I would like to find a filter for the receving
> optics which blocks 365nm (less than .01% transmission) and passes
> 400nm to 500nm (greater than 90% transmission).
>
> Surprisingly, I have found only ONE material which does this. Yes,
> schott, hoya, etc.. make colored filter glass specificaly GG400 and the
> like, but that glass AUTOFLUORESCES when exposed to 365nm and is
> basically worthless for this experiment.
>
> The one material I have found which does a TERRIFIC job is the plastic
> that UVEX clear safety glasses are made of. Its cheap, it does not
> autofluoresce, and it has fantastic 365nm blocking and 400nm pass
> through. The blocking at 365nm is so strong, I can actually put the
> excitation source and the receiever butted up against each other (the
> excitation LED shining directly into the receiver an inch away) and if
> I put the clear safety glasses between them the 'signal' drops to
> almost nothing, from completely saturated! Amazing!! Especially
> considering this is a ultra-high gain lock-in amplifier!
>
> I called UVEX and the person I talked to didn't know anything about the
> material. I have read on the internet that it may be made by rohm and
> haas.
>
> Please, does anyone know of a filter that has these charateristics, or
> a source for the same kind of plastic used in UVEX sunglasses?
>
> Yes, I know I can just use the saftey glasses, but this device will
> become a commercial one, and I don't think cutting up safety glasses
> for each unit is realistic.
>


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