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M3-01. Michelson Interferometer - Laser Light


To show that the speed of light in air is different from the speed of light in a vacuum.


Michelson interferometer with laser, gas cell with hand pump.

Setup Time

5 minutes.




This experiment uses the laser and white light combination Michelson interferometer setup, which remains set up and aligned and only needs the light source to be installed. The system is pre-aligned according to procedures in the f ile. The laser light is expanded by a 2 cm focal length convex lens and reflected into the interferometer by a front surface plane mirror, sitting beside the laser in the photograph. Either circular or straight line fringes can be displayed by adjusting the tilting mirror (at the right on the interferometer). The light exiting the interferometer is focused onto a di


Eric F. Cave and Louis V. Holroyd, Inexpensive Michelson Interferometer, AJP 23, 61, (1955). ◙T. G. Bullen, Notes on an Inexpensive Form of Michelson's Interferometer, AJP 27, 520-521, (1959). ◙G. Friedmann and R. Vidal, Modification to an Inexpensive Interferometer, AJP 30, 604, (1962). ◙Hans Weltin, Light Beats, AJP 30, 653-654, (1962). ◙Gary C. Babcock, The "Sagnac" Interferometer, AJP 30, 311, (1962). ◙Physics II Laboratory Manual, Expt IV The Michelson Interferometer, (1968). ◙Edward M. Parma and B. C. Thompson, Interferometer Demonstrations for Large Classes, AJP 39, 1091-1092 (1971). ◙F