interferometer

(noun)

Any of several instruments that use the interference of waves to determine wavelengths and wave velocities, determine refractive indices, and measure small distances, temperature changes, stresses, and many other useful measurements.

Related Terms

Examples of interferometer in the following topics:

  • The Michelson Interferometer

    • The Michelson interferometer is the most common configuration for optical interferometry.
    • The interferometer works by splitting a beam of light into two paths, bouncing them back and then recombining them to create an interference pattern.
    • Figure 3 shows a diagram of how a Michelson Interferometer works.
    • The Michelson Interferometer has been used for the detection of gravitational waves, as a tunable narrow band filter, and as the core of Fourier transform spectroscopy.
    • This diagram of a Michelson Interferometer shows the path that the light waves travels in the instrument.

  • Air Wedge

    • An air wedge is a simple interferometer used to visualize the disturbance of the wave front after propagation through a test object.
    • An air wedge is one of the simplest designs of shearing interferometers used to visualize the disturbance of the wave front after propagation through a test object.
    • The interferometer consists of two optical glass wedges (~2-5 degrees), pushed together and then slightly separated from one side to create a thin air-gap wedge.
    • An example of an air wedge interferometer is shown in .
    • Because of this extremely thin air-gap, the air wedge interferometer has been successfully used in experiments with femto-second high-power lasers.

  • Relativistic Addition of Velocities

    • Using a Michelson interferometer, Hyppolite Fizeau measured the speed of light in a fluid moving parallel to the light in 1851 .