the path of light through a medium, having a magnitude equal to the geometric distance through the system times the index of refraction of the medium.
noun 1. a film printer used in making optical effects, consisting basically of a camera that photographs the image with special lenses to enlarge, reduce, distort, etc., and a projector that transfers the image to the print stock, as distinguished from a contact printer.
noun, Physics, Optics. 1. a method for increasing the number of atoms or molecules occupying higher energy levels by irradiating them with light of the proper frequencies to raise them to those levels.
- Optical pyrometer
noun 1. See pyrometer
- Optical resonator
optical resonator 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.