by vasimv » Thu Oct 31, 2019 8:02 am
Martin wrote: ↑Thu Oct 31, 2019 3:05 am
That's amazing. What's your gelatin? The last time I tried this with my standard gelatin I was only able to record some dim transmission gratings.
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 Methylene blue too but my red laser is quite weak to test as the emulsion requires many hundreds of mJ/cm2 exposure. Later i plan to test if i do really need TEA as my success could be just because i've got right pH adjustment with the recipe. The gelatin is "Superclear 300 bloom" -
https://www.amazon.com/gp/product/B00FGZAXII
Best i've got so far with TEA/TMG (had to underexpose it a bit as it tends to do big blue shift in good exposed areas, perhaps because high concetrations of TEA+TMG):
- DSC_2024.JPG (142.03 KiB) Viewed 14192 times
Martin wrote: ↑Thu Oct 31, 2019 3:05 am
I don't know about other diazos but with D.A.S. TEA or TMG are not compatible. But I seem to remember spectrally sensitized diazo materials mentioned by Kosar's book.
Hmm. May be just add a dye to the DAS emulsion? The speedball diazo has some dye in it but looks like it was optimized for far-blue region.
Martin wrote: ↑Thu Oct 31, 2019 3:05 am
The PL530 is good news. Is there a way of purchasing a system (being completely illiterate in regards to electronics)?
I didn't found cheap ready systems with it. So, i've just made one with 2 switching regulators, peltier module, thermoresistor, arduino and MOSFET+LC filter (one regulator sets current for laser, other for its heater element and arduino with MOSFET regulates voltage on peltier module to keep laser assembly's temperature at 25C with 0.1C precision). Perhaps not good idea to use switching regulator for the laser diode (voltage ripples may cause diode's mode switching) but looks ok. I plan to make final version soon (fully made of assembled regulator modules and microcontroller board) which should be easy to assemble by anyone who can use a soldering iron, will post it on forum when ready. Full price for the stuff would be in $120..150 range.
Martin wrote: ↑Thu Oct 31, 2019 3:05 am
Yet I'd love to see also a 405nm laser of decent quality/at a reasonable price.
Seems only way is to buy 100..300 mW diodes and run them on very low power with good cooling to get some quality. There are crystals that could be used to increase laser frequency (like in green lasers) to make DPSS UV-laser but i haven't found cheap ready modules with it.
Martin wrote: ↑Thu Oct 31, 2019 3:05 am
As for speeding up your process, you might add a monomer to your solution. I got decent holograms with good speed when adding acrylamide and methylenebisacrylamide to the gelatin-TMG-dye solution. The holograms were extremely sensitive to humidity though. Of course, we'd have to find less hazardous monomers compatible with gelatin...
Sodium acrylate (NaO) perhaps? People use it as direct replacement of acrylamide in photopolymer systems. But i wasn't able to obtain some.
[quote=Martin post_id=71380 time=1572509115 user_id=2364]
That's amazing. What's your gelatin? The last time I tried this with my standard gelatin I was only able to record some dim transmission gratings.
[/quote]
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 Methylene blue too but my red laser is quite weak to test as the emulsion requires many hundreds of mJ/cm2 exposure. Later i plan to test if i do really need TEA as my success could be just because i've got right pH adjustment with the recipe. The gelatin is "Superclear 300 bloom" - https://www.amazon.com/gp/product/B00FGZAXII
Best i've got so far with TEA/TMG (had to underexpose it a bit as it tends to do big blue shift in good exposed areas, perhaps because high concetrations of TEA+TMG):
[attachment=0]DSC_2024.JPG[/attachment]
[quote=Martin post_id=71380 time=1572509115 user_id=2364]
I don't know about other diazos but with D.A.S. TEA or TMG are not compatible. But I seem to remember spectrally sensitized diazo materials mentioned by Kosar's book.
[/quote]
Hmm. May be just add a dye to the DAS emulsion? The speedball diazo has some dye in it but looks like it was optimized for far-blue region.
[quote=Martin post_id=71380 time=1572509115 user_id=2364]
The PL530 is good news. Is there a way of purchasing a system (being completely illiterate in regards to electronics)?
[/quote]
I didn't found cheap ready systems with it. So, i've just made one with 2 switching regulators, peltier module, thermoresistor, arduino and MOSFET+LC filter (one regulator sets current for laser, other for its heater element and arduino with MOSFET regulates voltage on peltier module to keep laser assembly's temperature at 25C with 0.1C precision). Perhaps not good idea to use switching regulator for the laser diode (voltage ripples may cause diode's mode switching) but looks ok. I plan to make final version soon (fully made of assembled regulator modules and microcontroller board) which should be easy to assemble by anyone who can use a soldering iron, will post it on forum when ready. Full price for the stuff would be in $120..150 range.
[quote=Martin post_id=71380 time=1572509115 user_id=2364]
Yet I'd love to see also a 405nm laser of decent quality/at a reasonable price.
[/quote]
Seems only way is to buy 100..300 mW diodes and run them on very low power with good cooling to get some quality. There are crystals that could be used to increase laser frequency (like in green lasers) to make DPSS UV-laser but i haven't found cheap ready modules with it. :(
[quote=Martin post_id=71380 time=1572509115 user_id=2364]
As for speeding up your process, you might add a monomer to your solution. I got decent holograms with good speed when adding acrylamide and methylenebisacrylamide to the gelatin-TMG-dye solution. The holograms were extremely sensitive to humidity though. Of course, we'd have to find less hazardous monomers compatible with gelatin...
[/quote]
Sodium acrylate (NaO) perhaps? People use it as direct replacement of acrylamide in photopolymer systems. But i wasn't able to obtain some. :(