Who hasnt ever wanted to build their own interferometer?

What is an interferometer you might ask?

An interferometer is any device that takes advantage of the property of light that allows light to interfer with itself.

The device i built is called a Michelson interferometer. The design is simple: it splits "laser light" into two beams allowing each beam to take a slightly longer path.

Then it will recombine the light into a single spot where the light rays will then "interfere" with eachother similar to waves in the ocean, creating peaks and valleys. The peaks being bright spots and the valleys being dark spots.



-2 Mirrors


-Negative Lens

-Piece of white paper to View image


We set up the interferometer as shown with the beam splitter in the center at a 45% angle to the laser. then set up the mirrors at two sides of the interferometer with the remaining open side place the diverging negative lens.


The tricky part is trying to get the two beams to intersect at the same point just before the negative lens so they will interfere with eachother. you can experiment with the alignment, when you take the two beams apart the fringes will disapear, and when you recombine the beams the fringes will magically reappear. Btw this whole set up is very vibration sensitive, which is one reason i did it on a concrete floor.


The set up

Red Laser diode


The fringes



a little movie showing the moving fringes due to vibration and settling Movie 30mb

The green set up

The fringes



If i can do it without an expensive set up so can you.

and even you sid.


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