Report of a Green Laser Pointer Hologram!

Colin Kaminski · Post by **Colin Kaminski** » Wed Mar 18, 2009 4:46 am

Hi Folks,
Been lurking on this site for a few months, reading and learning. What a great resource (thanks Colin)!
I've been interested in lasers and holography since I was a kid. However, school then family then career have a way of taking priority (lack of cash can be a factor too). So now career is starting to level off, or even slow down, and I find I have a bit more time to explore the things that interest me. Besides lasers/holography those things include geology, caving, scuba and hiking. I re-kindled my interest in holography when I obtained a large-frame argon laser. As it turns out, it was useless for holography, but it got me going nevertheless. My first holograms were made with a green laser pointer (the Jasper curve). It turns out that particular pointer makes pretty decent holograms and seems to have a coherence distance of about 10 inches give or take.... who'd have thunk it? I have now moved up to a JDS Uniphase microgreen. Pedal to the metal it give me 50 milliwatts. Just starting to play with that and still using VRP-M plates and JD-2 developer from Integraf. Well, that's about it by way of introduction. I intend to start posting some questions pretty soon. Hopefully, I won't be asking about to many things that have already been asked and answered over the years.

All the best to everyone on the Forum and a happy St. Patty's day to all.

Ron

Ron, This is quite exciting. The green pointer I tried was useless. This pointer you describe seems to be quite interesting. Welcome to the forum! We like answering questions we have already answered. It makes us feel smart. :whistle:

rzeheb · Post by **rzeheb** » Wed Mar 18, 2009 5:03 pm

Hi Colin,

Thanks for the warm welcome. I suppose one of the things I should learn is how to photograph and post pictures of holograms. I'll see if I can upload an example of a transmission hologram made with the Jasper pointer. What's your limit on image size?

Ron

Colin Kaminski · Post by **Colin Kaminski** » Fri Mar 20, 2009 3:02 am

I should know that! I think it is around 75K if the forum is hosting it. If it is hosted on another site I don't have a limit.

rzeheb · Post by **rzeheb** » Sat Mar 21, 2009 4:58 pm

Well, I tried to take some photos of my laser pointer holograms....... pretty pathetic results so far. I used to have a pretty good digital camera, but after it broke for the second time I got frustrated and decided not to have it repaired or replaced. So now I am stuck using my wife's point and shoot camera. It's hard to keep it from focusing on the plate rather than on the virtual image. I don't think it would add anything to post any of the pictures now. Maybe if I can get some better pictures I'll post later. I can tell you that the Jasper pointer definitely works for holos. The major flaw (other than my own technique errors such as drying artifacts, angle of reference beam, beam ratios, etc. etc.) is banding across the image presumably caused by mode hopping. I have no problems getting clear images of scenes at least 8 inches deep using single beam transmission, VRP-M plates and about 15s exposure times. I suspect that providing some form of temperature stabilization would further improve the quality of the images. However, now that I have the microgreen I don't plan on using the pointer for anything other than viewing already exposed plates..... oh, and maybe as a pointer.

rzeheb · Post by **rzeheb** » Sun Apr 12, 2009 3:01 pm

O.K. I decided to get over my embarrassment and post a picture of my laser pointer generated hologram. It has many defects for all to see, including drying streaks (didn't squeege, but now I do) and writing on the plate, but it is a hologram. The banding is presumably due to mode hopping.

: elephant.jpg (91.95 KiB) Viewed 3860 times

Colin Kaminski · Post by **Colin Kaminski** » Sun Apr 12, 2009 11:39 pm

Thank you for posting the photo! It also looks like light was entering the edge of the plate. Make sure to tape off or paint the edges of the plate before exposure.

danielpower · Post by **danielpower** » Sat Mar 27, 2010 8:02 am

Thanks for your hard effort.

John Klayer · Post by **John Klayer** » Sat Mar 27, 2010 10:10 pm

Hummm? A green pointer works? You're a caver too. Welcome to the Forum.

Sergio · Post by **Sergio** » Sat Mar 27, 2010 11:16 pm

I also report some transmission holograms (gratings mainly) with some tiny 1mm reflection hologram areas, with a >50mW laser pointer the TEM00 transverse mode (moving the x-tal axis) can be well adjusted until certainly a 00 blob appear Gaussian. The thermal pumping quality and temperature control seems the key for narrow line-width because the cavity is mm short..

rzeheb · Post by **rzeheb** » Sun Mar 28, 2010 11:32 am

I never thought that old thread would pop up again..... or maybe I just wish it didn't. I look at that old holo now and cringe.

Funny, I remember how happy and proud I was when I first made it. I guess you have to start somewhere but it sure is nice to climb up that learning curve.