# Resonance

Resonance — MC Grating documentation for Modal Crossed and Chandezon Crossed. The resonance search is aimed at searching for anomalies of the reflected and…

Canonical: https://mcgrating.com/docs/common-crossed/resonance.html


Written by Nikolay M. LyndinLast revised 2016-10-16

This documentation was written for releases up to 2018 and is being revised. Some dialogs have changed since. If something does not match what you see, write to [mc@mcgrating.com](mailto:mc@mcgrating.com).

- The resonance search is aimed at searching for anomalies of the reflected and the transmitted waves when the incidence angle is changed in a fixed incidence plane. These anomalies could be caused, for example, by excitation of the waveguide modes the dielectric structure under modeling. The incidence plane is defined in the ***General*** page. It looks for the *pole* parameters (position - ***angle*** and ***width***) associated with the reflection (transmission) anomaly (resonance) of the selected polarization (***Polarization Output***). At the page opening the software automatically estimates the waveguide parameters by calculating the mode effective indexes of the multilayer structure under the assumption of a structure with real refractive indexes, the grating regions being considered as suitably averaged uniform layers. The exact resonance search can then be performed for a defined initial resonance position - ***angle*** and ***width*** with the button ***Find*** and iteratively improved with the same button changed to ***Repeat***. The main resonance parameters are calculated on the basis of the phenomenological resonance response approximation by *poles* functions using five (single resonance) or seven (double resonance) equidistant angular positions located within an angular range covering four ***Half Resonance Width*** symmetrically with respect to the resonance ***Angle*** position.
 If the ***Double Resonance*** check box is checked two consecutive poles will be calculated. This double resonance search is obligatory in two cases: first under normal incidence, secondly in the case of two neighboring resonances (poles).
- The full set of *poles* parameters can be found after the resonance searching in an appropriate page of ***[Analysis](https://mcgrating.com/docs/common-crossed/analysis.html)*** dialog.
- The all fields and controls of this page are rather obvious.

From the in-application help of Modal Crossed, documented through 2018. If you publish results computed with MC Grating, see [how to cite it](https://mcgrating.com/references.html#cite).