<tr>
<td> [[Image:MATER MAN22.png|thumb|left|480px|The fixed-temperature PTC dialog.]] </td>
</tr>
</table>
== Gaussian Beam ==
ICON: [[File:gauss_icon.png]]
MODULE: [[EM.Tempo]]
FUNCTION: Defines a focused Gaussian beam source with specified incidence angles, polarization, beam focus point and beam radius
TO DEFINE A GAUSSIAN BEAM:
# Right-click on the '''Plane Waves''' item in the navigation tree.
# Select '''Insert New Source...''' to open up the Plane Wave Dialog.
# By default, a TMz-polarized plane wave source is defined with normal incidence along the negative Z-axis.
# You can change the '''Polarization''' type and incident '''Theta''' and '''Phi''' angles in the spherical coordinate system.
# Click the '''OK''' button of the dialog to return to the project workspace.
NOTES, SPECIAL CASES OR EXCEPTIONS: Unlike plane waves, a Gaussian beam is a localized field. By default, the dominant fundamental Hermite-Gauss mode H<sub>00</sub> is assumed. You can define a higher-order Hermite-Gauss mode by assigning nonzero values for the modal indices '''p''' and '''q'''.
{{note|The beam radius has to be at least λ<sub>0</sub>/π; otherwise, strong fields appear outside the excitation box.}}
PYTHON COMMAND: gauss_beam(label,theta,phi,polarization,focus_x,focus_y,focus_z,radius,p_mode,q_mode)
GAUSSIAN BEAM PARAMETERS
{| class="wikitable"
|-
! scope="col"| Parameter Name
! scope="col"| Value Type
! scope="col"| Units
! scope="col"| Default Value
! scope="col"| Notes
|-
! scope="row" | polarization
| List: TMz, TEz, Custom Linear
| -
| TMz
| select one of the linear or circular polarization types
|-
! scope="row" | theta
| real numeric
| degrees
| 180
| incident elevation angle
|-
! scope="row" | phi
| real numeric
| degrees
| 0
| incident azimuth angle
|-
! scope="row" | focus_x
| real numeric
| project units
| 0
| X-coordinate of beam focus point
|-
! scope="row" | focus_y
| real numeric
| project units
| 0
| Y-coordinate of beam focus point
|-
! scope="row" | focus_z
| real numeric
| project units
| 0
| Z-coordinate of beam focus point
|-
! scope="row" | radius
| real numeric
| project units
| 10
| beam waist radius
|-
! scope="row" | p
| integer numeric
| -
| 0
| first index of Hermite-Gauss mode
|-
! scope="row" | q
| integer numeric
| -
| 0
| second index of Hermite-Gauss mode
|}
<table>
<tr>
<td>
[[Image:GaussBeam.png|thumb|left|480px|The Gaussian beam source dialog.]]
</td>
</tr>
</table>
