Lasers Flashcards
What are the three processes for interaction between a solid and a photon
Absorption, spontaneous emission, and stimulated emission.
Describe the basics of absorption
Describe the operation of a heterojunction laser
All lasers use predominately stimulated emission to generate photons.
This process requires population inversion to enhance the stimulated emission. In heterojunction lasers, the carriers are confined to the active region via the heterojunction barriers. The light produced is also confined via the abrupt decrease in refractive index. This light is guided via total internal reflection out of the waveguide.
As the photon leaves it will likely stimulate more emission.
Describe the process of photon generation for a laser.
A laser generates photons principally by stimulated emission. For this to occur an electron-rich environment must exist in the excited state. This is population inversion. For this to occur a stable intermediary state is required between the valence and conduction bands.
