Hello,

I´m looking for a material which has a spectral selective reflectance.
The requirements are to have a very high reflectance (>80%) from
visible up to approximately 2µm and to have a very low or no
reflectance from 2 up to 5 µm.

This is in contrast to coatings which are usually used for our solar
cell products where a low reflectance is required from visible up to
approximately 2µm and a high reflectance starting at 2µm (see e.g.
http://www.solar4ever.de/selektivitaet.htm).

Best regards

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Request for Question Clarification by mathtalk-ga on 29 Jan 2004 07:13 PST

Hi, engineer5555-ga:

Are you looking for transparency in the 2-5 µm wavelengths, or
absorbtion?  Or does it not matter for your intended application.

regards, mathtalk-ga

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Clarification of Question by engineer5555-ga on 29 Jan 2004 08:17 PST

Hello mathtalk-ga,

thank you for your question. 

The material I´m looking for should absorb infrared radiation in the
range 2-5µm. It should be a single material, not multi thin film
layers.

It is clear that most probably no material exists, which has exactly
the required properties. The best material I found so far is Al2O3 in
pigments used in white color paints.

So if a material could be found which has better spectral reflectance
than Al2O3 that would answer my original question.

Best regards,
engineer5555-ga.

Optical Coating Laboratory, Inc.
http://www.ocli.com/