PIRA 6D40.10 Interferometers: Michelson interferometer
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Photo Shows the Demonstration Used at the University
of Texas at Austin.
Instructions / Notes:
Michelson interferometer shown above is for a large classroom.
- This version of a Michelson interferometer utilizes:
- A 5 mW laser
- A lens between the laser and beam spitter slightly expands the laser beams.
- A double-prism beam splitter
- Two front surfaced mirrors
- Only one mirror has an X versus Y adjustment
- The second mirror has an adjustment towards or away from the beam spltter
Room lights must be dimmed for students to see the projected interference fringes, shown below.
- At the bottom-left of one mirror is a horizontal adjusting screw to move one of the reflected laser beams to the left or right.
- Only a slight tweak on the adjustment knob significantly the moves the reflected pattern either into or out of alignment.
- A slight tweak is about a 5 degree turn of the adjustment knob.
Photo shows the interference pattern with both reflected laser beams overlapped. (Notice that the room lights have been dimmed.)
Demo staff: Please set up the demo cart so it is about 6 feet from the wall or one of the white prep-room doors, so the class can see the merged beams.
Small adjustments in the mirrors or noise in the room will greatly alter the interference fringes.
Last Updated 3/17 - University of Texas at Austin Physics Dept.
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