1. Spontaneous Emission in Quantum State
Jongmin Lee

2. Photon Emission Process
Stimulated emission
Spontaneous emission

3. Spontaneous Emission Rate
Dominant recombination paths of carriers in direct bandgap semiconductor --> LED Most common source of photon provided by nature

4. Spontaneous Emission
Vacuum field strength
Vacuum field induced transitions can occur with no classical field stimulation, we refer to them as spontaneous emission event.
For the understanding
What is vacuum field
How we can get a spontaneous emission rate with vacuum field

5. Quantum Theory for Photon
Old quantum theory
First quantized – atomic levels are quantized
Electromagnetic wave is not
Extended to second quantized theory
Quantum electrodynamics (QED)
Relativistic quantum field theory of electrodynamics

6. Dirac Sea
Theoretical model for vacuum

7. Vacuum State Quantum state with lowest possible energy
No means a simple empty space
Short-lived virtual particle-antiparticle pairs

8. SE in micro cavity
Purcell effect
Vacuum field renormalization factor

9. SE Rate in Micro Cavity

10. Thank you!