Periodic Condition

The sets up a periodicity between the selected boundaries.


	The software usually automatically identifies the boundaries as either source boundaries or destination boundaries, as indicated in the selection list. This works fine for cases like opposing parallel boundaries. In other cases, right-click Periodic Condition and select Manual Destination Selection to control the destination. By default it contains the selection that COMSOL Multiphysics identifies.

Destination Selection

This section is available for specifying the destination boundaries, if needed, when the option is selected in the context menu for the node. You can only select destination boundaries from the union of all source and destination boundaries.

Periodicity Settings

Select a — (the default), , , or . Select:

•

to make the electric field periodic (equal on the source and destination),

•

to make it antiperiodic,

•

(The Electromagnetic Waves, Frequency Domain Interface and The Electromagnetic Waves, Beam Envelopes Interface only) to use a Floquet periodicity (Bloch–Floquet periodicity),

For also enter the source for the .

For specify the components of the kF (SI unit: rad/m).

For the kF is obtained from the settings.

The phase shift between the fields on the parallel source and destination boundaries is defined as

•

for azimuthal periodicity in a structure consisting of a number of identical sectors.

When is set to (the default), the sector angle is automatically computed from the geometry. Set to to enter a manual value for the θs (SI unit: rad).

Enter an integer number for the m.

The phase shift between the fields on the source and destination boundaries is defined as

Constraint Settings

To display this section, click the button (

) and select in the dialog box. For information about the section, see Constraint Settings in the COMSOL Multiphysics Reference Manual.

Orientation of Source

To display this section, click the button (

) and select in the dialog box. For information about the section, see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual.

Orientation of Destination

This section appears if the setting for in the section is changed from the default value, , and is selected in the dialog box. For information about the section, see Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual.

Mapping Between Source and Destination

To display this section, click the button (

) and select in the dialog box. For information about the section, see Mapping Between Source and Destination in the COMSOL Multiphysics Reference Manual.


	Periodic Boundary Conditions


	Fresnel Equations: Application Library path Wave_Optics_Module/Verification_Examples/fresnel_equations Plasmonic Wire Grating: Application Library path Wave_Optics_Module/Gratings_and_Metamaterials/plasmonic_wire_grating