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Laser Physics I PH481/581-VT (Mirov)
Optical Frequency Amplifiers
Lectures 3-4 chapter 2
Fall 2015C. Davis, “Lasers and Electro-optics”
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Optical Frequency Amplifiers
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Homogeneous Line Broadening
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e(+iot
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Inhomogeneous Broadening
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Homogeneous Line Broadening
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Inhomogeneous Broadening
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Optical Frequency Amplification with a Homogeneously Broadened Transition
B21
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‘Pump area
Z2
'212
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Cross section of emission ( , )8c A g
gN Ng
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The Stimulated Emission rate in a Homogeneously Broadened Transition
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21 3( ) ( , )8
eA c I IW gh h
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Optical Frequency Amplification with Inhomogeneous Broadening
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L
• – ’ : distance from line center• L : Lorentz half-width• D : Doppler half-width
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'2 2
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2 ln 2( , ) Normalized Voight Profile( )
2( ) ln 2 2 ln 2ln 2 , , and ,
where is shift in central frequency due to molecules collision
t
D
L
D D D
y eg dty x t
y x t
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Optical Frequency Oscillation - Saturation
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Power output from a laser amplifier
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Inhomogeneous system
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