Holograms
Parts / Tools
1 Sheet of Transparency Film
Smart Phone w/ LED or LCD screen
Scissors
Printer
Transparent Tape
Holograms can be seen in a variety of objects in every day life: credit cards, federal IDs, and driver's licenses all include simple holograms to stop forgery. Many children books have simple holograms to create visual effects. Some currency even has simple holograms verify authenticity!
Holograms are three-dimensional images that appear as you tilt or move an object containing such hologram. Just like a camera takes a picture of an object and produces a two-dimensional image, your brain "snaps" two pictures of an object through your eyes and combines them to create a three-dimensional image. This is how virtual reality headsets produce three-dimensional worlds on a two-dimensional screen.
The holograms seen in science fiction, however, are more than simple visual tricks. These objects are "floating" in the air, not simply projected as two images. These holograms are commonly made of three-dimensional images reproduced from a pattern of interference from a split coherent beam of radiation (such as a laser). First discovered in the 1940’s by Hungarian-British physicist, Dennis Gabor, electron holography was the unintentional brainchild of electron microscope advancements. With the invention of the laser in the 1960’s, holography quickly adapted to its modern optical counterpart created by Yuri Denisyuk. These holograms used silver halide (a compound of silver and a halogen) as a medium, producing a very inefficient optical render. Industrial holograms today follow this Gabor-style Hologram, but utilizing x-ray free-electron lasers, or particle accelerators, instead of the x-ray devices employed by Gabor himself, which produces shorter wavelengths and thus higher resolution.
The commonly used commercial hologram, known as the Denisyuk Hologram, or Reflection Hologram, simply refracts visible light onto a slanted, translucent medium to produce an image suspended on said medium. These holograms do not use lasers, which make them easier to produce, but much lower quality. Today, we will be creating a Denisyuk "Reflection" Hologram.
Terminology
Hologram - three-dimensional images reproduced from a pattern of interference from a split coherent beam of radiation (such as a laser)
Denisyuk Hologram - Reflection holograms; produced by the refraction of light through a medium.
Gabor Hologram - Laser holograms; Electron holography; produced within particle accelerators using free-electron lasers to produce a higher resolution hologram.
Refraction - Light or other wavelengths being deflected while passing between one medium and another or through a medium of varying density. Refraction can work through lenses, prisms, and other non-opaque objects. Refraction can be seen when light curves through a medium.
Reflection - Not to be confused with refraction, reflection redirects all visible wavelengths in a new direction, not absorbing any wavelengths. Reflection can be seen when light is mirrored through an opaque medium in a new direction.
Print Cutting Template
Please print the following cutting template. You can print this template either on paper or directly on to your transparency film.* When printing directly on transparency, use the template without measurements to allow the hologram to be clear and without being covered.
Cutting Template without measurements
If you would rather measure the pieces by hand, begin by cutting out a 16.5cm x 6cm rectangle from your transparency paper. Next, using an expo marker, make marks along one of the long sides of this rectangle at 6cm, 7cm, 13cm, and 14cm. Rotate the paper so that the marked side is now on top and repeat the process. Starting at the corner of your rectangle, create a line to the closest mark on the opposite side. Continue making these lines between each closest mark until you have 4 trapezoids and 2 right triangles. Use the cutting template as a visual aid during this process.
*Do not print on transparency film if you use a laser printer. The laser will melt the film and ruin your printer. Allow ink to dry for 24 hours before using to reduce smearing.
Cut Out The Area
Using scissors, cut out a single rectangle of transparency measured 16.5cm x 6cm. This area can be found four times on each cutting template. Only a single rectangle is necessary for one hologram device.
Cut Out The Shapes
Using scissors, cut the transparency rectangle along the dashed lines, as shown in the cutting template. If you used paper to print your cutting template, it may be helpful to tape your transparency film on top of your cutting template. You should create 4 trapezoids of equal length (6cm) and height (6cm), with waste of two right triangles.
Create Stabilizing Legs
On each trapezoid, fold the side with length of 1cm up about 2mm. This fold side will be used as a leg to keep the hologram device sturdy. Due to the device being very light, you may need to adjust this leg's length later to increase sturdiness. Bend these legs back out to create a 90 degree angle with the rest of the trapezoidal side.
Prepare the Tape
Using scissors, cut transparent tape into 8 pieces about 1/2 cm in length and the width of the tape as is. Apply 2 pieces to a single side of each trapezoid (excluding the sides of length 1cm and 6cm). To ensure the best stability, place one piece near the top and one piece near the bottom of this side.
Assemble the Hologram Device
With each trapezoid's leg side facing towards the same direction, place one taped side next to an untaped side and combine the two. Continue in this method until three sides are taped together.
When attaching the fourth side, lift the device into a pyramid-like shape to complete the figure.
*TIP: For the best stability and picture, ensure each side is flush to its adjacent sides. Also, ensure the legged sides are lined up to create a flush connection with the table for standing.
Test It Out!
Play this video on your smart phone and make sure to full screen it! Place your hologram device in the center of your screen with the "X" marking the center. Sit back and enjoy the Holograms show!