Coupled mode theory

From the coupled mode theory, it is possible to retrieve a modified phase matching condition, which is more accurate than (3.1)26 ... 

Yariv, A., 1973, Coupled-mode theory for guided-wave optics, IEEE J. Quantum Electron. QE-9(9) 919-933. 

Numerics has been used intensively in the field of integrated optics (10) since its early days, simply due to the fact that even the basic example of the slab waveguide requires the solution of a transcendental equation in order to calculate the propagation constants of the slab- guided modes. Of course, the focus was directed to analytical methods, primarily, as long as the power of a desktop computer did allow for a few coupled equations and special functions only e.g. to describe the nonlinear directional coupler in a coupled mode theory (CMT) picture. During the years, lots of analytic and semi-analytic approaches to solve the wave equation have been developed in order... 

The existence of the nonlinear polarization field does not ensure the generation of significant signal fields. With the exception of phenomena based on an intensity-dependent refractive index, the generation of the nonlinearly produced signal waves at frequency cos can be treated in the slowly varying amplitude approximation with well-known guided wave coupled mode theory (1). As already explicitly assumed in Equation 1, the amplitudes of the waves are allowed to vary slowly with... 

This simple description does not take into account the so-called photonic stop-band effect, which forbids propagation at wavelength exactly satisfying the Bragg condition. According to the coupled mode theory [66, 67], distributed feedback (DFB) lasers normally oscillate on the edge of this photonic stopband (Figure 15.14). 

The most general theory of dynamic properties in the critical region, namely, the coupled modes theory, leads to scaling plots, that are justified by experimental data. 

Extensive treatment of optical waveguide and directional coupler theory has been addressed by many researchers for both continuous two-dimensional film waveguides and dielectric strip waveguides. Various methods, such as dielectric waveguide, coupled-mode theory, effective index, the beam propagation method, and finite-element analysis, have been used [15,24,25,75,77,78,83,89-114]. Analysis of these methods shows good agreement between all of the different models. 

Taylor, H. E, and Yariv, A., Guided wave optics, Proc. IEEE, 62, 1044 (1974). Hardy, A., and Streifer, W., Coupled mode theory of parallel waveguides, J. Lightwave Technol, LT-3, 1135 (1985). 

Fujisawa T, Koshiba M (2006) Analysis of photonic crystal waveguide gratings with coupling-mode theory and finite-element method. Appl Opt 45(17) 4114-A121... 

The coupled mode theory is often used to describe the polarization characteristics, or modes coupling in optical fibre, and the reflection spectra of FBG sensors. When the optical response of an optical fibre is analysed based on the coupled mode theory, the electric field is normalized as j j E ( E (dxdy = 1. Based on the perturbation approach, the slowly varying amplitudes c are determined by the following coupled mode equations ... 

Unlike the optical responses of an FBG sensor under tension, the sensitivity of the Bragg wavelength shift of an FBG sensor under torsion is very small. However, the polarization response to torsion is significant. The coupled mode theory can be used to analyse the polarization behaviour of an FBG sensor under torsion. ... 

Marcuse, D. (1973) Coupled mode theory for round optical fibers. Bell Syst. Tech. J., 52, 817-18. 

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