LASER (Light Amplification by Stimulated Emission of Radiation)

LASER (Light Amplification by Stimulated Emission of Radiation) Points : laser (light amplification by stimulated emission of radiation) The Laser is like the LED but emit light in a different way, resulting in a higher output powers and more directional beams. The beam is produced by a cavity resonator that reflects light again and again through the excited medium. The cavity consists of a pair of mirrors, one at each end of the region occupied by excited atoms. The light emitted toward one mirror is reflected again and again between the two mirrors thus stimulating emission from electrons. This causes the intensity of light of identical wavelength and phase to become large even at low overall light intensity, so that the stimulated emission begins at low injected currents. The basic operation of the laser is shown in the figure.