Hello all,

I'm trying to identify possible materials / vendors for a broadband (vis-MWIR)
optical absorbing layer to be integrated in an optical MEMS device.  In the
past, we've used a spin-coatable black polyimide for the purpose (purchased from
Brewer), but they no longer make or sell the material.  Wondering if anyone has
suggestions for an alternative vendor or material.  What we're looking for:

* High broadband optical absorption.  Ideally a single material spanning the
entire range from ~300-5000 nm would be good, but sets of materials with broad
absorption bands (eg one for visible, one for 3000 - 5000 nm) would also work.
Ideally absorption should be high enough to perform well at sub-wavelength
coating thicknesses.

(Good absorption at i- and g-line wavelengths to act as a kind of BARC during
photolithography would be a bonus, but not a requirement.)

* Spin coatable.

* Electrical resistivity as high as possible.  Given that one way to make such a
material is by impregnating carbon black in a polymer matrix, I understand that
getting a truly insulating material may be tough.

* Patternable.  Ideally a diretly photopatternable material would be wonderful;
if not, something amenable to a lift-off or etch process (say O2 RIE with a hard
mask) would be sufficient.

* Long life.  This will be a permanent part of the optical device; polymers that
can be crosslinked or otherwise cured would be preferable.

If anyone has suggestions for vendors or even particular materials, I'd be
grateful.

-Mike