Definition of "interferometer" [in•ter•fe•rom•e•ter]

• Any of several optical, acoustic, or radio frequency instruments that use interference phenomena between a reference wave and an experimental wave or between two parts of an experimental wave to determine wavelengths and wave velocities, measure very small distances and thicknesses, and calculate indices of refraction. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Michelson's interferometer is capable of an application no less significant than those which we have already considered."
• "The instrument in question, known as the interferometer, had previously yielded a remarkable series of results when applied in its various forms to the solution of fundamental problems."
• "Chu was one of the originators of the atom interferometer, which is based on his Nobel Prize-winning development of cold laser traps."