2.6.4
Types of Optoelectronic Oscillators by the
Composition of Modulated Light Source . . . . . . . . . . . . 36
2.6.5
OEO Division According to FOS Topology . . . . . . . . . . 37
2.7
Modern Elements of OEO: A Laser, the Optical Fiber,
and a Photodetector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.7.1
A Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.7.2
Optical Resonators and the Optical Fiber . . . . . . . . . . . . 39
2.7.3
Fiber Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.7.4
The Optical Modulator in OEO and Modules . . . . . . . . . 44
2.7.5
Optical Fibers for OEO and Photodiodes . . . . . . . . . . . . 44
2.8
Comparison of OEO Characteristics with Other Traditional
Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.8.1
Traditional Electronic Oscillators . . . . . . . . . . . . . . . . . 47
2.8.2
Q-factors of Oscillator Resonance Systems . . . . . . . . . . 50
2.8.3
Dimensions of Oscillator Resonance Systems . . . . . . . . . 53
2.8.4
Phase Noises and PSD of Precision RF Oscillations . . . . 56
2.9
Modern Optoelectronic Methods for Precision RF Oscillation
Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.9.1
Commercial Bulky and Compact Frequency Standards
with Optical Pumping on Cesium and Rubidium
Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.9.2
A Synthesizer with the Fabry–Perot High-Q
Resonator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.9.3
A Synthesizer with the Optical Micro-Resonator . . . . . . 61
2.10 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3 Modulation Methods of Laser Emission in Optoelectronic
oscillator (OEO) and OEO Differential Equations . . . . . . . . . . . . . . . 73
3.1
Direct and External Laser Modulation in OEO . . . . . . . . . . . . . . 74
3.1.1
The Structure of OEO Analysis . . . . . . . . . . . . . . . . . . . 75
3.1.2
Variants with Direct and External Modulations . . . . . . . 76
3.1.3
Heterodyne Transformation and Self-Heterodyning
in OEO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
3.1.4
Quantum Nature of Laser Noises in OEO . . . . . . . . . . . 88
3.1.5
Variants of OEO Operating Structures . . . . . . . . . . . . . . 89
3.2
Methods of Modulation and Heterodyning of Laser
Emissions at DM and MZ Modulations . . . . . . . . . . . . . . . . . . . 93
3.2.1
Method of Direct Amplitude Modulation . . . . . . . . . . . . 94
3.2.2
Modulation and Heterodyning in OEO MZ . . . . . . . . . . 102
3.3
Mathematical Description of Transfer Functions of OEO
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
3.3.1
The Optical Amplifier for the Laser . . . . . . . . . . . . . . . . 108
3.3.2
Optical Filter of a Laser . . . . . . . . . . . . . . . . . . . . . . . . 109
3.3.3
The Photodetector in OEO . . . . . . . . . . . . . . . . . . . . . . 111
xiv
Contents
Types of Optoelectronic Oscillators by the
Composition of Modulated Light Source . . . . . . . . . . . . 36
2.6.5
OEO Division According to FOS Topology . . . . . . . . . . 37
2.7
Modern Elements of OEO: A Laser, the Optical Fiber,
and a Photodetector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.7.1
A Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.7.2
Optical Resonators and the Optical Fiber . . . . . . . . . . . . 39
2.7.3
Fiber Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.7.4
The Optical Modulator in OEO and Modules . . . . . . . . . 44
2.7.5
Optical Fibers for OEO and Photodiodes . . . . . . . . . . . . 44
2.8
Comparison of OEO Characteristics with Other Traditional
Oscillators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
2.8.1
Traditional Electronic Oscillators . . . . . . . . . . . . . . . . . 47
2.8.2
Q-factors of Oscillator Resonance Systems . . . . . . . . . . 50
2.8.3
Dimensions of Oscillator Resonance Systems . . . . . . . . . 53
2.8.4
Phase Noises and PSD of Precision RF Oscillations . . . . 56
2.9
Modern Optoelectronic Methods for Precision RF Oscillation
Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.9.1
Commercial Bulky and Compact Frequency Standards
with Optical Pumping on Cesium and Rubidium
Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
2.9.2
A Synthesizer with the Fabry–Perot High-Q
Resonator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.9.3
A Synthesizer with the Optical Micro-Resonator . . . . . . 61
2.10 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
3 Modulation Methods of Laser Emission in Optoelectronic
oscillator (OEO) and OEO Differential Equations . . . . . . . . . . . . . . . 73
3.1
Direct and External Laser Modulation in OEO . . . . . . . . . . . . . . 74
3.1.1
The Structure of OEO Analysis . . . . . . . . . . . . . . . . . . . 75
3.1.2
Variants with Direct and External Modulations . . . . . . . 76
3.1.3
Heterodyne Transformation and Self-Heterodyning
in OEO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
3.1.4
Quantum Nature of Laser Noises in OEO . . . . . . . . . . . 88
3.1.5
Variants of OEO Operating Structures . . . . . . . . . . . . . . 89
3.2
Methods of Modulation and Heterodyning of Laser
Emissions at DM and MZ Modulations . . . . . . . . . . . . . . . . . . . 93
3.2.1
Method of Direct Amplitude Modulation . . . . . . . . . . . . 94
3.2.2
Modulation and Heterodyning in OEO MZ . . . . . . . . . . 102
3.3
Mathematical Description of Transfer Functions of OEO
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
3.3.1
The Optical Amplifier for the Laser . . . . . . . . . . . . . . . . 108
3.3.2
Optical Filter of a Laser . . . . . . . . . . . . . . . . . . . . . . . . 109
3.3.3
The Photodetector in OEO . . . . . . . . . . . . . . . . . . . . . . 111
xiv
Contents