Hi, I'm new here!

bernardb · Post by **bernardb** » Fri Oct 26, 2007 9:33 pm

Hi All,

I am very happy that Colin has this forum! I have never made a hologram yet but I think I have everything I need (almost). I have been collecting parts for over a year but got distracted for many many months by other issues. Now I am almost ready to start up again.

I am wanting to make blue holograms using a Melles Griot Argon laser, do you peeps think this will work? I mean, will the hologram have a blue tint to it when viewed? Can you guys please have a look-see at the laser I have in mind here:

http://gallery.mac.com/bernardmac#gallery

Thanks for the help.

DrOutlier · Post by **DrOutlier** » Fri Oct 26, 2007 9:56 pm

8) As long as it's a true laser (monochromatic and coherent) all you need to know is that its TEM is rated at 00. Any other TEM is bad.

As an Automan fan I have no objection to blue holograms.

bernardb · Post by **bernardb** » Sat Oct 27, 2007 1:17 am

DrOutLier,

Thanks for the reply. What do you mean by "true laser"? Is there some other kind I should know about?

Thanks for your help.

Bernard

Tom B. · Post by **Tom B.** » Sat Oct 27, 2007 5:43 am

I tried the site and it kept coming back to the browser complaint page, even though I checked the don't bug me and use current browser buttons (I'm using Seamonkey 1.15). Anyway, the solution was to allow cookies - I normally run with paranoid cookie settings where I get prompted for any cookie stuffing requests but here it didn't get that far...

Re blue holos, if the laser works you should be able to make holos, though an argon laser without an etalon will have a limited coherence length meaning that great care must be taken in match object-reference path lengths and the depth is limited to a few inches. The major problem is that blue-sensitive holographic plates are not a commonly stocked item. Some sources that can provide them on special order:

http://www.ultimate-holography.com/GB/I ... nglais.htm

http://www.colourholographic.com/Plateproducts.htm

Unfortunately the latter only sells big plates for this wavelength and the cost is high. For completeness I should mention that you could eventually go with making your own DCG (dichromated gelatin) plates, but this is not exactly easy to do. Some prior experience with making holograms with known-good materials is almost essential (i.e. you would be nuts to try making your first hologram this way - but don't let that stop you!)

For your first holos, I'd recommend one of the inexpensive Integraf kits which includes a small (red) diode laser which is generally well regarded:

http://www.holokits.com/holography_kit_2.htm

Don't cheap out, go with the plates - film is just too painfully fussy and the results are never as good as plates.

glajciorz · Post by **glajciorz** » Sat Oct 27, 2007 10:03 pm

Hi Bernardb

I saw you use a SSY1. Is it K*P crystal in the mount ? If so - why not be a little extravagant and make your first holo with a pulsed setup ? I know it's a little unusual path for a beginner, but maybe worth considering.

greetings
Adam

P.S. I like the wooden SSY1 PSU box

60J of pure energy inside - WOW !

DrOutlier · Post by **DrOutlier** » Sun Oct 28, 2007 12:59 am

8) Bernard,

For example, a "white light laser" where you can have spatial coherence but not the monochromatic feature.

bernardb · Post by **bernardb** » Sun Oct 28, 2007 3:33 pm

OKay, I understand now about the white light laser - (not monochromatic) thanks for the info!

The SSY1 does indeed have a KTP. The whole contraption I bought from Bill Jensen who is a regular here(?). I commissioned him to create a pulsed green laser for me to use in holography - I am saving it for when I know what I'm doing!

Too bad about the argon, I read in the specs it has a coherence length of 10cm and I guess that is too short, right?

My problem has been I have been looking for a powerful laser with long coherence length suited to making deep holograms but they are just TOO dam expensive. Maybe I just don't understand enough yet because I get the impression that the "cheap" diode lasers have a long coherence length, is that right? If so, what is their drawback that keeps them from being perfect for holography?

I have a nice new ThorLabs Optical Breadboard (4 x 6 ft), tons of holders, adjusters, beamsplitters, a spatial filter, etc. etc. I have a "lab" in my garage that is still in the making, I need to blacken it to outside light, set up my developing area, and get some AC.

I have been wanting to get my feet wet with holography for years now, just keep running into my own lack of knowledge...whaaaa...

Thanks for all the help!

Bernard

(I have a post in the Pulsed forum about another laser I have...)

glajciorz · Post by **glajciorz** » Sun Oct 28, 2007 4:29 pm

The SSY1 does indeed have a KTP. The whole contraption I bought from Bill Jensen who is a regular here(?). I commissioned him to create a pulsed green laser for me to use in holography - I am saving it for when I know what I'm doing!

Good

Fired it already ?
About IR filter - you can use a green IR filter from an old VHS camcorder. It passes 1% of 1064nm light.

My problem has been I have been looking for a powerful laser with long coherence length suited to making deep holograms but they are just TOO dam expensive.

Want to make deep holos ? Look for the Melles-Griot 05-LHP-121 HeNe. Few days ago I bought one for $65, together with its PSU. Only 3mW, but I saw a Denisyuk with a depth at least 18cm made with this little guy (so CL is at least 36cm).
If you used PFG-01 presensitized with TEA or hydroquinone you could make nice 4x5" holograms with exposures below 30s.

greetings
Adam

DrOutlier · Post by **DrOutlier** » Sun Oct 28, 2007 10:19 pm

8) Bernard,

I am Just curious since you mentioned your garage. Do your neighbors know about this and how understanding are they about a homemade lab in the neighborhood?

Colin Kaminski · Post by **Colin Kaminski** » Mon Oct 29, 2007 3:27 am

The diode laser from Integraf has never failed me and makes holograms that are about 6" deep. Perhaps deeper as I have not found the edge. For $35 for 5mw that is not too bad. The higher power diodes have more problems that you can find out about in the wiki.