Amplified spontaneous emission

Superluminescent or amplified spontaneous emission (English amplified spontaneous emission, ASE short ) is generated due to spontaneous emission light that has been optically amplified by stimulated emission at a lasing medium.

It occurs when the laser medium is excited by optical pumping to create a population inversion. Superluminescent is an effect that results in Q-switched lasers to power loss, since as on a locked Q-switch stimulated by spontaneous photon emission occurs and the inversion is already partially degraded before the Q-switch opens.

The feedback of the superluminescent in the laser cavity can lead to laser action when the lasing threshold is exceeded. As such, it is a condition for the oscillation of each selbstanschwingenden laser.

In optical amplifiers it can lead to self- destruction, but at least limits the maximum stage gain. It increases the signal background, that is, it is generated spontaneously when no input signal radiation.

Superluminescent superluminescent diodes is used in order to generate light with a large line width, a low temporal coherence but a high spatial coherence.

• Laser Physics