Related Experiment Video
Updated: Feb 12, 2026

Calibration Procedures for Orthogonal Superposition Rheology
Published on: November 18, 2020
Assessment of the orthogonal and non-orthogonal coupled-mode theory for parallel optical waveguide couplers
Abstract:
The coupled-mode theory (CMT) is a powerful approach routinely used to calculate the effects of spatial mode interactions in perturbed structures, such as optical waveguides. One of its basic hypotheses requires that perturbations are weak. This is usually not the case for devices fabricated with modern semiconductor-based technologies. In this paper, the CMT is studied in these critical cases to assess its validity. Attention will be focused on the quite common case of parallel coupled waveguides. For these structures, results can in fact be compared to the exact ones, obtained using super-modes. The study will show that not all the possible expressions of the coupling coefficients are equivalent, and which one can be pragmatically used to obtain results with minimum errors with respect to exact solutions.
Related Concept Videos
Orthogonal Trajectories
Theory of Romantic Attachment in Adulthood
Band Theory
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
Scientific Laws and Theories
What is a Mode?
There can be more than one mode in a data set if multiple values have the same highest frequency. For instance, suppose that the Statistics exam scores of 20 students are: 50; 53; 59; 59; 63; 63; 72; 72; 72; 72; 72; 76; 78; 81; 83; 84; 84; 84; 90; 93. Here, the mode is 72, as it occurs most frequently, five times.
A data set with two modes is called bimodal. For example,...
Attribution Theory

