Book contents
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Part I Signals, spectra and optical modulations
- Part II Principles of light polarization and optical amplification
- Part III Interferometric optical modulators
- 8 Theory of the single-mode optical coupler
- 9 Theory and applications of the Mach–Zehnder interferometer
- 10 Interferometric optical responses
- 11 Chirp theory of the Mach–Zehnder modulator
- 12 Theory and modeling of the quadrature Mach–Zehnder modulator
- Part IV
- Appendix A Electromagnetic energy and power flow
- Appendix B Optical power and photon flux
- Index
- References
8 - Theory of the single-mode optical coupler
The synchronous compound waveguide
from Part III - Interferometric optical modulators
Published online by Cambridge University Press: 05 September 2014
- Frontmatter
- Dedication
- Contents
- Preface
- Acknowledgments
- Part I Signals, spectra and optical modulations
- Part II Principles of light polarization and optical amplification
- Part III Interferometric optical modulators
- 8 Theory of the single-mode optical coupler
- 9 Theory and applications of the Mach–Zehnder interferometer
- 10 Interferometric optical responses
- 11 Chirp theory of the Mach–Zehnder modulator
- 12 Theory and modeling of the quadrature Mach–Zehnder modulator
- Part IV
- Appendix A Electromagnetic energy and power flow
- Appendix B Optical power and photon flux
- Index
- References
Summary
Introduction
In this chapter, we will present the coupled-mode theory of an ideal single-mode optical coupler, according to work originally developed by Dietrich Marcuse [1]. Section 8.2 introduces and discusses some relevant concepts of the generic four-port linear system, with particular reference to the optical coupler.
The classical approach to the coupled-mode theory of the directional optical coupler is presented in Section 8.3. The transition from isolated-waveguide to compound-waveguide modes, and the growth of field interference owing to different propagation constants, are highlighted as fundamental principles of the optical field coupling mechanism. In order to provide quantitative examples, the Gaussian model of even and odd compound modes is presented in Section 8.4, to be used for simulations and examples of field patterns through this chapter. The Gaussian field approximation takes its strength from a heuristic approach and the simplicity of its mathematical description. The excitation of a compound waveguide by superposition of fields is analyzed in Section 8.5, leading to the formulation of the coupled-waveguide equations.
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- Theory and Design of Terabit Optical Fiber Transmission Systems , pp. 587 - 662Publisher: Cambridge University PressPrint publication year: 2014