Recommend cheap laser pointers for holography?

Simple answers are here! For Theory look in General Holography.
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dave battin

Recommend cheap laser pointers for holography?

Post by dave battin »

Hi guys, i wanted to assemble some holography starter kits and was wondering about what current red laser pointers work for holography ?
Any suggestions will be greatly received. thanks DB
jnhong

Recommend cheap laser pointers for holography?

Post by jnhong »

There are hundreds of laser pointer manufacturers out there. That makes it hard to source a specific model of laser pointer and be assured that it will be the same specification throughout the years you sell your kit. That said, you don't really want a laser pointer if you're doing a kit. What you really need is a Laser Diode Module, the same as provided by Integraf or LitiHolo in their kits. LDMs have a built-in voltage regulator and can be driven by a battery pack. (See my previous post on red laser diodes.)

The only way you can assure that all your kits use the same LDM throughout the years is for you to purchase a huge lot of them at one time, or find an extremely reliable supplier who will churn out the same LDMs year after year after year. Or you can just test every time you order a new batch of modules. That's probably the most practical approach.

As for the LDM specs themselves, most red laser diodes are okay for holography. From my little bit of experience, the coherence length is pretty good (~100 mm), the longitudinal mode is typically single for low-power diodes (<5 mA), and the TEM, usually 00 but sometimes not, is not as significant. Sacrilege!! But TEM-xx is still coherent. You just get some dark spots in your plate. For experimenters and first-timers who don't know any better, what's the big deal?

Since you've been working on this idea for a while now, what have you learned about laser pointers and/or laser diode modules, wrt basic holography? Exactly what concerns did you have regarding suitability for holo recording? I'm sure you've read Frank de Freitas' page on diode holos and you've tried Integraf's kit. What issues did you see?
Colin Kaminski

Recommend cheap laser pointers for holography?

Post by Colin Kaminski »

I have one vote for the Integraf module. I have used three. I think they are about $25 if you look for it. Less in quantity.

Stick with less than 5mw and they all have worked for me, except for one that had internal reflections making the beam unstable. I had a bet for a few years that I could make a hologram with any less than $10 laser. After about 10 models I lost on one shaped like a bullet and had a shiny bore for the beam.

Posted with TouchBB on my iPhone
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