lock-in amplifier(redirected from Phase sensitive detector)
Also found in: Acronyms.
lock-in amplifier[′läk‚in ′am·plə‚fī·ər]
An amplifier that uses some form of automatic synchronization with an external reference signal to detect and measure very weak electromagnetic radiation at radio or optical wavelengths in the presence of very high noise levels.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.