7.2.7
The Model of Nonsymmetrical Waveguides
in MZ Optical Channels . . . . . . . . . . . . . . . . . . . . . . . . 388
7.2.8
OEO as the Correlator with Utilization of Spatial
Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
7.3
OEO DM Analysis on the Base of Abbreviated Differential
Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
7.3.1
Structures of OEO DM and Features of OEO
Operation with the Direct LD Modulation
with Coherent Optical Self-Heterodyning . . . . . . . . . . . . 392
7.3.2
Quantum-Well Laser Diode in ОEO DM . . . . . . . . . . . . 392
7.3.3
QWLD Differential Equations and the Transfer
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
7.3.4
Frequency and Amplitude Control in OEO
with QWLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
7.3.5
The Effect of the Polarity Change of the Argument
Slope of the QWLD Transfer Function . . . . . . . . . . . . . 404
7.3.6
Modern QWLDs and Their Characteristics . . . . . . . . . . . 405
7.3.7
Brief Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
7.4
Frequency Control in OEO with RF FODL with Two
Optical Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
7.4.1
The Structure of OEO DM with RF FODL
with Two Optical Fibers . . . . . . . . . . . . . . . . . . . . . . . . 409
7.4.2
The Analysis of Transients in OEO with Differential
RF FODL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
7.4.3
The Analysis of the Generation Frequency Control
in OEO with the Differential RF FODL in the Steady
State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
7.4.4
The Frequency Control of OEO with the Differential
RF FODL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
7.4.5
The Frequency Control of OEO with the Differential
RF FODL on the Base of the Directional Y-Coupler . . . . 420
7.4.6
The Frequency Control in OEO with the Differential
RF FODL with the Directional Coupler of Х-Type . . . . 423
7.5
Parametric Frequency Instability of OEO with RF FODL
at Temperature Impact of the Single Optical Fiber . . . . . . . . . . . . 427
7.5.1
The Heating Process of Optical Fiber, Which Is
in Non-tensioned State for Free Thread Setting . . . . . . . 428
7.5.2
Prospects of the Ultrasmall RF FODL Development
Less than 1 cm
3 and with the Delay 5–50 μs/km . . . . . . 430
7.5.3
Parametric and Long-Term Frequency Instability
of OEO with the Differential RF FODL . . . . . . . . . . . . . 432
7.5.4
The Phase-Generator Measuring Method
of Differential Delays of the Optical Fiber
at Its Temperature Change . . . . . . . . . . . . . . . . . . . . . . 433
7.5.5
Brief Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
xx
Contents
The Model of Nonsymmetrical Waveguides
in MZ Optical Channels . . . . . . . . . . . . . . . . . . . . . . . . 388
7.2.8
OEO as the Correlator with Utilization of Spatial
Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
7.3
OEO DM Analysis on the Base of Abbreviated Differential
Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
7.3.1
Structures of OEO DM and Features of OEO
Operation with the Direct LD Modulation
with Coherent Optical Self-Heterodyning . . . . . . . . . . . . 392
7.3.2
Quantum-Well Laser Diode in ОEO DM . . . . . . . . . . . . 392
7.3.3
QWLD Differential Equations and the Transfer
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
7.3.4
Frequency and Amplitude Control in OEO
with QWLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
7.3.5
The Effect of the Polarity Change of the Argument
Slope of the QWLD Transfer Function . . . . . . . . . . . . . 404
7.3.6
Modern QWLDs and Their Characteristics . . . . . . . . . . . 405
7.3.7
Brief Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
7.4
Frequency Control in OEO with RF FODL with Two
Optical Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
7.4.1
The Structure of OEO DM with RF FODL
with Two Optical Fibers . . . . . . . . . . . . . . . . . . . . . . . . 409
7.4.2
The Analysis of Transients in OEO with Differential
RF FODL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
7.4.3
The Analysis of the Generation Frequency Control
in OEO with the Differential RF FODL in the Steady
State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
7.4.4
The Frequency Control of OEO with the Differential
RF FODL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
7.4.5
The Frequency Control of OEO with the Differential
RF FODL on the Base of the Directional Y-Coupler . . . . 420
7.4.6
The Frequency Control in OEO with the Differential
RF FODL with the Directional Coupler of Х-Type . . . . 423
7.5
Parametric Frequency Instability of OEO with RF FODL
at Temperature Impact of the Single Optical Fiber . . . . . . . . . . . . 427
7.5.1
The Heating Process of Optical Fiber, Which Is
in Non-tensioned State for Free Thread Setting . . . . . . . 428
7.5.2
Prospects of the Ultrasmall RF FODL Development
Less than 1 cm
3 and with the Delay 5–50 μs/km . . . . . . 430
7.5.3
Parametric and Long-Term Frequency Instability
of OEO with the Differential RF FODL . . . . . . . . . . . . . 432
7.5.4
The Phase-Generator Measuring Method
of Differential Delays of the Optical Fiber
at Its Temperature Change . . . . . . . . . . . . . . . . . . . . . . 433
7.5.5
Brief Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
xx
Contents