# Scanning

Scanning — MC Grating documentation for Modal Collinear and Modal Conical. The panel Scanning Range defines the initial and final values of the scanning…

Canonical: https://mcgrating.com/docs/modal/scanning.html


Written by Nikolay M. LyndinLast revised 2013-05-27

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 panel ***Scanning Range*** defines the initial and final values of the scanning parameter and the number of intervals (number of points minus one).
- The panel ***Scanning****** of*** has an obvious meaning. The first option ***Fixed Parameters*** corresponds to the ***[General](https://mcgrating.com/docs/modal/general.html)*** and ***[Layers](https://mcgrating.com/docs/modal/layers.html)*** page parameters.
 - Scanning of ***Layer Thickness*** enables the Check Box ***Bunch***. This control checking implies the total thickness of selected layers scanning preserving their relative thicknesses.
 If it is necessary only changing at ones the Bunch of Layers Thickness, press*** OK*** →*** Optimize ***→*** [Variable Parameters](https://mcgrating.com/docs/common/variable.html)***,** **edit *Bunch of Layers Thickness *and press ***Export*** → ***Settings*** to return back.
 - The ***Cell Length*** is normalized for the period and its scanning has two options. The unselected or disabled Check Box ***Center*** implies that a sum of lengths of given Cell and the next Cell is constant. The selected and enabled Check Box ***Center*** (this is possible only for number of cells more than two) implies that the given Cell center position is preserved and a sum of lengths from previous to the next Cell is constant.
 **Note** The ***Bunch*** option is used in Optimization Dialog and cannot be edited from it.
- If the check box in the ***2D scan of*** panel is checked then the user can get diffraction efficiency versus two different parameters from the ***Scanning of*** panel list. The diffraction efficiency order and component can be selected in the ***Diffraction Orders Output*** panel and in the ***2D scan of*** panel Combo Box. Scanning parameters, range and number of scanning points can be selected individually for rows and columns under appropriate ***2D scan of*** option.
- The other controls: ***Output Format, Output Decimal Digits*** and ***Diffraction Orders Output*** define the representation of result data in the edit window.
 In the panel ***Diffraction Orders Output*** the user can choose any range of displayed diffraction orders restricted by minus plus of a half ***Number of Modes***. Near by the appropriate fields there are tips about the extreme indexes of diffraction orders in the whole range of scanning which are updating with the changes of scanning range parameters.
- The conical mount version contains the ***Output Polarizer* **control. This control has an effect only on the result data representation and not on the actual calculations. For more details see ***[Slider](https://mcgrating.com/docs/common/slider.html)***.

A one dimensional scan is represented in an appropriate graphics window. See the ***[Graph Dialog](https://mcgrating.com/docs/common/graph.html)***.
 A two dimensional scan is represented in the [***3D*** ***Graph***](https://mcgrating.com/docs/common/graph-3d.html) window.

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