Search found 92 matches

by Martin
Tue Nov 19, 2019 9:50 am
Forum: Optics
Topic: Ruby LASER for holography
Replies: 6
Views: 644

Re: Ruby LASER for holography

That's absolutely amazing! Congratulations!
by Martin
Sat Nov 02, 2019 4:39 am
Forum: DCG
Topic: Diazo gelatin (DIAG)
Replies: 7
Views: 2264

Re: Diazo gelatin (DIAG)

Martin wrote:
Sat Nov 02, 2019 4:21 am
I was thinking of improving mode stability/coherence length of a cheap 405nm diode...
See: https://www.coherent.com/assets/pdf/Sin ... torage.pdf
by Martin
Sat Nov 02, 2019 4:21 am
Forum: DCG
Topic: Diazo gelatin (DIAG)
Replies: 7
Views: 2264

Re: Diazo gelatin (DIAG)

Found the patent for spectrally sensitized diazo by adding "dithiocarbamates" with dye: https://patents.google.com/patent/US3778274 Interesting. The question though is if the diazo materials mentioned in this patent are available and compatible with gelatin. Interesting, but if i understand correct...
by Martin
Fri Nov 01, 2019 3:49 am
Forum: DCG
Topic: Diazo gelatin (DIAG)
Replies: 7
Views: 2264

Re: Diazo gelatin (DIAG)

Well, it is one of my alchemy attempts, i've mixed safranin O dye, TEA and TMG (2 times more than TEA) in same emulsion (from my previous experience - TEA provides good holograms but weak sensitivity and TMG increases contrast and sensitivity but weak holograms alone). This should work with Methyle...
by Martin
Thu Oct 31, 2019 3:05 am
Forum: DCG
Topic: Diazo gelatin (DIAG)
Replies: 7
Views: 2264

Re: Diazo gelatin (DIAG)

Interesting. I'm busy experimenting with dye+TEA/TMG (no dichromates) emulsions now and got good holograms with it last week but plan to return to experiments with FEG and speedball diazo stuff some time later. That's amazing. What's your gelatin? The last time I tried this with my standard gelatin...
by Martin
Tue Oct 22, 2019 3:54 am
Forum: DCG
Topic: Diazo gelatin (DIAG)
Replies: 7
Views: 2264

Diazo gelatin (DIAG)

Just noticed that I might have had it wrong about D.A.S. (diazidostilbene-2,2'-disulfonic acid salt), diazo gelatin ("DIAG") - see https://holographyforum.org/forum/viewtopic.php?f=7&t=620&start=30. Luckily, I had some ethanol D.A.S. solution left, which I had kept in my fridge for more than six yea...
by Martin
Mon Sep 16, 2019 6:17 am
Forum: General Holography
Topic: Silver halide sensitivityy enhancer
Replies: 9
Views: 2465

Re: Silver halide sensitivityy enhancer

I recently published a brief article on the hypersensitization of silver halide emulsions using a formate pre-soak., which I first mentioned in the Forum more than a decade ago. Took me all this time to try it out. See: https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10558/105580C...
by Martin
Tue Sep 03, 2019 9:56 am
Forum: DCG
Topic: Ferric ammonium oxalate tests
Replies: 118
Views: 35583

Re: Ferric ammonium oxalate tests

I usually just add few drops of 10% soduium lauryl sulfate solution and it helps for gelatine and PVA emulsions enough to stay on the glass unless additional reprocessing with longer water exposure used. That's interesting. Usually surfactants are said to have a negative impact on layer adhesion (I...
by Martin
Thu Aug 22, 2019 2:40 am
Forum: General Holography
Topic: D.I.Y. holographic photopolymer
Replies: 26
Views: 11560

Re: D.I.Y. holographic photopolymer

Yes, exposed areas are water resistant, unexposed ones get washed off, like photoresist. IPA baths are useless, it has no effect. OK. So in order to record reflection holograms (and apply DCG-like processing) you'd have to pre-harden/crosslink the PVA prior to the holographic exposure. But using ge...
by Martin
Wed Aug 21, 2019 2:42 am
Forum: General Holography
Topic: D.I.Y. holographic photopolymer
Replies: 26
Views: 11560

Re: D.I.Y. holographic photopolymer

After reducing amount of sensitizer i've obtained some weak diffraction patterns from PVA + speedball sensitizer with transmission hologram copy, but it is really bad quality - i barely see some edges of shiny objects. Looks promising still (i like its simple developing process - just few minutes i...