A part of a laser, consisting of two mirrors, one highly reflective and one partly reflective, placed on either side of a laser pump. Amplified light bounces back and forth between the mirrors, enhancing stimulated emission within the pump, eventually being emitted through the partly reflective mirror. See more at laser.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.