How to make a hologram
“How can we use physics to make a hologram?”
Most photographs are composed in two dimensions. However, wouldn’t it be really cool if we could have three-dimensional photographs? Well, instead of just imagining it, let’s apply our engineering mindset to build it. To begin, let’s start off with a few tools, a laser, some lenses, a beam splitter, mirrors, and holographic film. Next, let’s point the laser to the beam splitter to divide the beam into two separate parts. Next, let’s direct both of these beams through diverging beams so they begin to “spread out”. Let’s also make sure that one of these beams (Called the “object” beam) envelops an object of our desired choice. The light impinging on this object will then be reflected, and let’s make sure that this light is directed onto a piece of holographic film. Let’s then use mirrors to guide the second beam of light (Called the “reference” beam) onto the mirror as well. The holographic film will capture the phase difference between the two beams, as well as the levels of darkness and light resulting from the reflection of the object. After all of this work, we would have just created our very own hologram! This process must be so precise that even vibration on the order of a ninth of the wavelength of the laser would destroy the image!