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As far as a simple test, my solution would be to add various concentrations of a specific dye to the emulsion, keeping all else constant (emulsion depth, bloom strength etc) then record two-beam gratings at various exposures and measure the DE. This is basically what we did for Martin and Sergio ab...

Of course, any testing with this material would be highly appreciated. Yes, the laser question really is of great importance. It would be nice to know up to what wavelength holograms can be made - without any spectral sensitization. The two laser modules I have are doing OK at rather low wavelengths...

Diazo-gelatin (DIAG). This is a follow-up to: https://holographyforum.org/forum/viewtopic.php?t=9629&start=10 Thanks by the way, vasimv, for pointing to SPEEDBALL. It appears that their diazo sensitizer for screen printing can be used to make holograms just like DCG. It's easy to use and  simple...

We showed this in 2004 by recording a surface relief hologram using the old 19th century Carbon printing process. We recorded with an interbeam angle of 30 degrees at 488nm, showing a resolution of about 1000 l/mm, high enough for a standard transmission hologram, though we could have gone as high ...

PRATHEEP wrote: ↑Sat Aug 14, 2021 6:50 am Does any one know of any suitable dyes other then Pinacyanol to sensitize silver halide emulsion to red laser 632.8 nm ?

3-carboxymethyl-3',9-diethyl-5,5'-dimethylthiacarbocyanine betain (it used to be available from
www.organica.de/en/products/dyes/) might be a good alternative for Pinacyanol.

They are quite startling, compared with the type of photographic images we're used to. The resolution looked extremely high, certainly I didn't see any hint of grain, and the images had a "solidity" that is hard to describe. Actually, it looks like resolution is high enough to record holo...

With our own material back then (DAROL photopolymer that is) one could easily "index match" the photopolymer side of the polyester film to a glass plate with water, glycerol, glycols etc. (if I'm not mislead it also worked with white spirit). One could even laminate it with a warm gelatin ...

Litiholo used to sell a blue (450nm) laser module - see: www.litiholo.com/hologram-lasers.html). Its power is only 5 mW though. Of course that's pretty moderate. Nevertheless, I could make holograms on DCG, FEG, photopolymer and diazo materials. The laser module I have works nicely without any mode-...

You may switch on an auxiliary incoherent light source during recording. This lowers the threshold energy required to initiate polymerization for the holographic (laser) exposure. It involves a lot of testing and fine tuning though.

That's absolutely amazing! Congratulations!