ttq 3-3 laser
DESCRIPTION
Each node within the domain namehierarchy is assigned to an authorityNote: The authority for a particular nodecan in turn delegate authority for lowerlevels of that node within the domainname hierarchyTRANSCRIPT
Content
• Semiconductor physics
• Light emitting diode (LED)
• Laser principles
• Laser diode• Laser diode
2
Laser (Light Amplification by
Stimulated Emission of Radiation)
3
Oscillator
4
Loss -> Large output bandwidth
5
Overcome loss -> Single frequency output
6
Fabry-Perot cavity
7
Optical oscillator (optical cavity) -> photon moving between two mirrors
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
8
Many frequencies satisfy the oscillating condition
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
9
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
10
Video: laser longitude mode
Absorption -> loss photon
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
11
Stimulated emission -> create photon
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
12
Stimulated emission -> Occur under “Population inversion” condition
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
13
2 energy levels -> Pump -> Transparency
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
14
3 energy levels -> pump -> population inversion
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
15
Video: light
amplification
Pump -> Population inversion -> Spontaneous emission
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
16
Spontaneous emission -> Oscillation condition
-> Stimulated emission -> Lasing
Cavity Gain PumpPopulation
Inversion
Stimulated
emissionLaser
17
Video:
simple laser