Michelson Interferometer (P12) [6D40.10]
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it as a quick visual of a Michelson interferometer in action when asking or answering questions about how fringes form and what mirror movement does.
Recommended by 1 people across 1 different months, 2017 to 2020.
What it is
A short MIT Physics Instructional Resources Lab demonstration of a Michelson interferometer measuring the wavelength of laser light. A beam is split into two paths and recombined on a screen, and the fringe pattern shifts as one path length is changed.
What people said
Recommends J Thomas · 2020-08 · Physics Stack Exchange · on “How does a Michelson interferometer work?”
First off, a Michelson interferometer does work. It can measure tiny length differences. Here is a video [this video] showing one in action. I must have misunderstood how it works. Here's what I think is happening: The light beam is split in two. The different paths may be different lengths. They are then recombined, and so they may interfere. [LINK] To see the interference, the light goes through a pinhole that is multiple wavelengths wide. The light spreads out in all directions, and when it hits a flat wall anywhere but the center, the light that went through different parts of the hole will have traveled different distances. So it interferes. All that matters is the geometry. The first dark c
Cites karthikeyan · 2017-07 · Physics Stack Exchange · on “Using multiple mirrors in Michelson Interferometer”
The number of mirrors typically used in Michelson Interferometer is 2. I am looking up the respective Wikipedia article [LINK] and MIT's youtube video [this video] . I am wondering, for the sake of one of my experiment, whether more than 2 mirrors can be used in the interferometer? I require the traversing mirror to be in a remote location and moving is a non-orthogonal line. I intend to use more mirrors to get the interference pattern. I wish to know if this is feasible. A pictorial representation is as this: [LINK]
Cites John D. · 2018-06 · Physics Stack Exchange · on “Average number of fringes”
Sorry for the error, but I followed youtube video which stated that a λ/2 'path difference' will produce identical patterns . [this video] . I guess I got 'path difference' confused with 'mirror path'.
Cites user191954 · 2018-07 · Physics Stack Exchange · on “Why does this wavemeter use $3$ mirrors to turn light $180^\circ$ instead of just $2$?”
I found the paper which introduces that diagram, so this the conclusion of this answer is largely based on claims made in that paper. Fox, P.J., et al. A reliable, compact, and low-cost Michelson wavemeter for laser wavelength measurement. Am. J. Phys. 67, 624 (1999) [LINK] . Free versions of the paper's pdf are available at INIS [LINK] and ResearchGate [LINK] . This is a bit long, and a lot of it is just a background about what's going on in that interferometer. The exact answer to the question's title is described in the last couple of sections. Here's the picture from the question again: [LINK] First, a brief overview of the purpose and working of this wavemeter: it measures the wavelengt