Open Boundary

The condition allows outgoing waves leave the modeling domain without being reflected back from the external boundary. It allows an optional incoming wave to be specified by the user. An advanced physics option allows the reversal of the open boundary condition: an unspecified incoming wave comes into the modeling domain through the boundary and no outgoing wave leaves the domain through the boundary.


	For stationary studies, an alternative for modeling nonreflecting outgoing waves is to use an exterior domain specified as a Perfectly Matched Layer to absorb the outgoing waves.

This setting specifies the outgoing wave type. Depending on the spatial dimension of the geometry, one or more of the following outgoing wave types may be supported: , and . If only one wave type is supported by the geometry, the drop down menu is grayed out and displays the supported wave type. If more than one is supported, the drop down menu is active and allows the user to make a selection.

The “no reflection” condition works well only if the outgoing wave propagating direction is normal to the boundary, otherwise some reflection will occur. Therefore for the type, the wave vector is assumed to be in the direction of the outgoing normal of the boundary.

For the type, enter the and one .

For the type, enter the .

This setting specifies an optional incoming wave if the check box is checked. The following settings may appear only if the check box is checked.

Incoming wave type

If more than one wave type is supported by the spatial dimension of the geometry, then the drop down menu appears and allow the user to make a selection.

For any incoming wave type, enter the ψ0. The default is 1.

For incoming , enter the .

For incoming , enter the and one .

For incoming , enter the .

Open Boundary Type

This setting is available if the is enabled by clicking the button (

) and selecting . Select either or .

This is the default. The open boundary allows outgoing waves leave the modeling domain without being reflected back from the boundary.

This reverses the usual open boundary condition: an unspecified incoming wave comes into the modeling domain through the boundary and no outgoing wave leaves the domain through the boundary. This particular option is mainly for analyzing resonant tunneling conditions, see the Double Barrier 1D tutorial in the Application Libraries.