Finding out whether my laser is suitable for holography

[highwaychile]

Hi,

for school I've to write a coursework "holography" including a practical part. Since we don't have a laser in school I can use, a friend of mine gave me one. My problem is: I've no idea whether it's appropriate for holography. I don't know its power, whether it's TEM00 and polarized. Unfortunately I don't even know the product name I've appended a picture of it.

I think that the problem with the polarization is solvable by using a simple polarizer (or does this cause any problems when creating a holograph?) , but how can I find out its mode and its power?

thanks in anticipation,

highwaychile

[Tom B.]

The object pictured is not a normal dollar-store laser pointer, looks much fancier. I wonder what it is. Does it emit a visible red beam?

The only sure way to check if it can make a hologram is to make a hologram, but as an intermediate step you could try to see if you can get stable fringes with a Michelson interferometer setup - there's a brief intro here: http://www.holowiki.com/index.php/Interferometry and much more elsewhere if you search.

Even with a good laser, you will still need a recording medium (film or glass plates) and chemistry to make a hologram. I highly recommend plates (much easier to get good results quickly). Some affordable complete kits including laser diode are available here: http://www.holokits.com/

If you need results quickly, though, maybe just demonstrating interference fringes with your laser or a $1.99 dollar store laser pointer plus some theoretical mumbo jumbo would be enough for your coursework. But unless you have a low vibration (quiet , no traffic) environment they can be hard to demonstrate.

[highwaychile]

Does it emit a visible red beam?

Yes, it does.

Even with a good laser, you will still need a recording medium (film or glass plates) and chemistry to make a hologram.

I know, I've already ordered Slavich PFG-01 films and Dokumol developer.

The only sure way to check if it can make a hologram is to make a hologram, but as an intermediate step you could try to see if you can get stable fringes with a Michelson interferometer setup - there's a brief intro here: http://www.holowiki.com/index.php/Interferometry and much more elsewhere if you search.

ok, I'll try this out. Assuming it doesn't work with my laser, would it be possible to use Infiniter 200 Laser pointer with Slavich pfg-01 though this film is not optimised for 670nm wavelength, as you can see below?

$28.95 for a laser would be a sum I can afford

If you need results quickly, though, maybe just demonstrating interference fringes with your laser or a $1.99 dollar store laser pointer plus some theoretical mumbo jumbo would be enough for your coursework. But unless you have a low vibration (quiet , no traffic) environment they can be hard to demonstrate.

No, the goal of my coursework is to ceate a hologram Luckily I've a quiet envionment, a cellar room and still 6 months left

highwaychile

[Tom B.]

No, the goal of my coursework is to ceate a hologram Luckily I've a quiet envionment, a cellar room and still 6 months left
highwaychile

In that case, I recommend one of the Integraf kits with diode laser and glass plates. Then you have some time left over to try to make film work

The point being that film is rather floppy and requires support unlike glass plates. And then to prevent ugly internal reflections, an index matching fluid is needed between the film and the glass support. And the film badly wants to curl and needs to be held down somehow. Of course it can be done, but it is just yet another thing to go wrong when you're starting out. Also results with glass plates just look better and are easier to show, unlike film which needs to be squashed flat. And PFG-01 is much coarser grained than the PFG-03M used with the plate kits. PFG-03 can have its own problems, but results when good are much brighter and clearer than PFG-01.

Also for inspirational books, I like Graham Saxby's "Practical Holography" and John Iovine's " Homemade Holograms".

[BobH]

That's an interesting laser in the picture. I see four parts. Can you describe what each part does? Do they all screw together for use, or they accessory parts? What is the diameter of it? Is there a name of date on it? Thanks!

For your holography experiment, I'd recommend looking for a small "lab" type he-ne laser. You'll have no issues with laser mode, beam power stability or coherence length. Laser "pointers" might be useable, but I don't recommend them for first attempts despite their low cost.

[highwaychile]

That's an interesting laser in the picture. I see four parts. Can you describe what each part does?

The biggest part seems to be the laser itself, the 2 small parts are power supplies (battery / electricity network [the one with the writing "MAIN MODULE SIMO VI"]). The 4th part may be screwed in center and causes to laser to blink instead of providing a constant ray. The laser's diameter is about 4,5 cm. Unfortunately the laser has no date, the only thing that's written is "laserpointer"; the box also has a writing "ROX" but that seems to be the producer of the box

For your holography experiment, I'd recommend looking for a small "lab" type he-ne laser.

Do you have an example of a laser that is appropriate and affordable? The wiki gives only quite expensive examples

In that case, I recommend one of the Integraf kits with diode laser and glass plates.

This looks good, but as I've already bought 30 holography films I'm unsure whether it's really necessary to buy another 12 plates that have to be shipped from America to Germany, but I'll keep it on my emergency list

highwaychile

[Tom B.]

This looks good, but as I've already bought 30 holography films I'm unsure whether it's really necessary to buy another 12 plates that have to be shipped from America to Germany, but I'll keep it on my emergency list
highwaychile

Ah, didn't realize you were out there. I seem to be recall that PFG-01 wasn't too bad as far as film flatness was concerned, but once you see your first holograms you will want to do some research on stabilizing the film (squashing it between glass plates) and index matching to reduce internal reflections. A forum search will turn up many discussions on these topics. I recommend allowing lots of settling time before exposure (i.e. the time allowed for things to settle down after you stop fiddling with the setup before you open the shutter) - maybe start at 15 minutes?