Vibration Isolation:
Because the precison of the holographic pattern is on the scale of the size of the wavlengths of light, the hologram making apparatus needs to be isolated from movements caused by the environment, either vibrations or wind currents. The simplest contraption is to simply set things up on a concrete floor! At the other extreme, expensive rigid vibration isolation tables made of granite, concrete or metal plates floating on cushions of air are used in professional holographic studios, such as those made by TMC or Newport Corporation. A less expensive option is a box of sand with optics mounted on plastic plumbing, as described in many books like Holography Handbood by Unterseher, Schlesinger, and Hansen, or How to Make Holograms by Don MacNair, amongst others. But the sandbox takes up a lot of dedicated space, so this author advocates a device he calls "The Big Beam", which does the job and can be taken apart and put away when not in use!
Light Source:
A laser is essential, and there are so many types available, but not all are suitable for making holograms, as coherence is a major issue. See Laser Sam's FAQ for more details. A great source of inexpensive, useful ones are available from his partner, Phil Bergeron contact him at pbergero@usf.edu.
Beam Spreading:
A laser beam is ray-like, so it needs to be enlarged. Simple single lenses can be used, but their drawback is that specks of dirt on them cause annoying diffraction pattern in the spread beam. A device called a Spatial Filter not only spreads out the beam, but can eliminate that annoying noise.
Mirrors:
For a couple of projects, part of the spread laser beam is steered into postion by a mirror. An ordinary household mirror is not usable, as there are reflections from not only the reflectiive metallic coating, but from the glass fron surface, causing a wood grain looking pattern in the spread beam. For this reason mirrors used in optics labs have their relfective coatings on their front surface, which makes them difficult to clean, but there are no artifacts.
Holographic Recording Materials:
Holographc quality films and plates using conventional photographic technology are available from a few manufacturers, with the Ultimate series being the ultimate in qualty, available from Ultimate Holography.in France. They can be quite pricey. Sometimes plates from Ilford/Harman Technology can be found, and they work quite well, on a par with the late, lamented Agfa-Gevaert products, which can sometimes be found on eBay, but your are taking your chances buying old stock. The Slavich Company in Russia also makes plates, not my first choice, but they are available from Integraf in America or Geola in Lithuania. Chemicals for processing them are available pre-packaged from Photographers Formulary in Montana, USA, or you can compound them from scratch suing recipes fround here on this web site.
If your are squeamish about dealing with photo-chemistry, (which is not that deadly), there are some self-developing holographic recording materials, but be fore-warned that price one pays the price for this convenience with exposure doses about 10 to 100 more intense than the above. These photopolymers are available from Liti Holographics in the US, or from the afore-mentioned Geola in Europe.
There is no excuse to not indulge!
<Introduction> <Equipment> <The Big Beam> <Project 1a: In-line "Gabor" type Holograms> < Project 1b: Off-Axis Holograms> < Project 2: Single Beam Transmission Deep Scene Hologram> <Project 3: Division of Amplitude Hologram> <Project 4: Pseudo-Achromat Transfer Hologram> <Project 5: Cylindrical Hologram> <Project 6: Single Beam Reflection Hologram> <Project 7: Image Plane Reflection Hologram> <Bonus Project 1: Diffraction Gratings> <Bonus Project 2: Holoroids>